Twin cities are a special case of two cities or urban centres that are founded in close geographic proximity and then grow into each other over time, losing most of their mutual buffer zone.
There are no precise criteria for twin-cityhood, but to be considered twin cities, the cities involved have to have a similar administrative status and somewhat comparable sizes; a suburb of a much larger population center is usually not considered to form a twin city with it. For example, South San Francisco (population about 65,000) is not considered a twin city with San Francisco (population about 850,000). However, cities considered twinned by proximity do not necessarily match demographically, economically, or politically.
In many historical cases, cities that grew into each other's space lost their individual identities, and the border or barrier originally separating them became almost irrelevant. An 1873 case of twin cities merging to become a united city is Budapest in Hungary, which began as two settlements (Buda and Pest) facing each other across the Danube at a strategic fording place along a trade route. In China, the three ancient cities of Hankou, Hanyang, and Wuchang, separated by the junction of the Yangtze and Hanjiang rivers, were joined in 1927 into the single entity of Wuhan.
Twin cities may share an airport into whose airport codes are integrated the component initials e.g. BWI (Baltimore-Washington), DFW (Dallasâ"Fort Worth), LBA (Leedsâ"Bradford), MSP (Minneapolisâ"Saint Paul, Minnesota), RDU (Raleigh and Durham, NC), and CAK (Akronâ"Canton, Ohio).
In some cases, such as Albury/Wodonga in Australia, the two cities are permanently divided by a state border, often one that strictly adheres to a geographical landmark, such as the Murray River that divides New South Wales from Victoria, and thus Albury from Wodonga. In other cases twin cities can be divided by an international border, but retain a cultural and historical similarity, for example Haparanda (Sweden) and Tornio (Finland), Leticia (Colombia) and Tabatinga (Brazil) or Valga (Estonia) and Valka (Latvia).
Examples
Americas
North America
- Canada
- Battleford and North Battleford, Saskatchewan "The Battlefords"
- Dartmouth, Nova Scotia and Halifax
- Gatineau, Quebec and Ottawa, Ontario Also Known as the Ottawa-Gatineau Metropolitan Area
- Kitchener-Cambridge-Waterloo
- United States
- Alcoa and Maryville, Tennessee
- Allentown and Bethlehem, Pennsylvania
- Auburn and Lewiston, Maine
- Auburn and Opelika, Alabama
- Benton Harbor and St. Joseph, Michigan
- Bloomington and Normal, Illinois
- Bluefield, Virginia and Bluefield, West Virginia
- Bossier City and Shreveport, Louisiana
- Bristol, Tennessee, and Bristol, Virginia
- Bryan and College Station, Texas
- Centralia and Chehalis, Washington
- Champaign and Urbana, Illinois
- Colorado City, Arizona and Hildale, Utah
- Dallas and Fort Worth
- Duluth, Minnesota, and Superior, Wisconsin
- Durham and Raleigh, North Carolina
- Easton, Pennsylvania and Phillipsburg, New Jersey
- Fargo, North Dakota, and Moorhead, Minnesota
- Fitchburg and Leominster, Massachusetts
- Grand Forks, North Dakota and East Grand Forks, Minnesota
- Greensboro and Winston-Salem, North Carolina
- Greenville and Spartanburg, South Carolina
- Gulfport, Mississippi and Biloxi, Mississippi
- Hartford, Connecticut and Springfield, Massachusetts
- Killeen and Temple, Texas
- Lafayette and West Lafayette, Indiana
- Lancaster and Palmdale, California
- Lansing (west), and East Lansing, Michigan
- Macon and Warner Robins, Georgia
- Marinette, Wisconsin and Menominee, Michigan
- Midland and Odessa, Texas
- Minneapolis and Saint Paul, Minnesota
- Monroe and West Monroe, Louisiana
- Montague and Whitehall, Michigan
- Norfolk and Virginia Beach, Virginia
- Portland and South Portland, Maine
- Petersburg and Richmond, Virginia
- Reno and Sparks, Nevada
- San Francisco and Oakland, California
- Scranton and Wilkes-Barre, Pennsylvania
- Sherman and Denison, Texas
- South Bend and Mishawaka, Indiana
- St. Petersburg, Florida and Tampa
- Texarkana, Arkansas and Texarkana, Texas
- Union City, Indiana and Union City, Ohio
- Wahpeton, North Dakota and Breckenridge, Minnesota
- Yuba City and Marysville, California
- Mexico--United States border
-
- San Diego, California, United States and Tijuana, Baja California, Mexico
- Calexico, California, United States and Mexicali, Baja California, Mexico
- Yuma, Arizona, United States and San Luis Rio Colorado, Sonora, Mexico
- Nogales, Arizona, United States and Nogales, Sonora, Mexico
- Douglas, Arizona, United States and Agua Prieta, Sonora, Mexico
- Columbus, New Mexico, United States and Las Palomas, Chihuahua, Mexico
- El Paso, Texas, United States and Ciudad Juarez, Chihuahua, Mexico
- Presidio, Texas, United States and Ojinaga, Chihuahua, Mexico
- Del Rio, Texas, United States and Ciudad Acuña, Coahuila, Mexico
- Eagle Pass, Texas, United States and Piedras Negras, Coahuila, Mexico
- Laredo, Texas, United States and Nuevo Laredo, Nuevo Leon, Mexico
- Mcallen, Texas, United States and Reynosa, Tamaulipas, Mexico
- Brownsville, Texas, United States and Matamoros, Tamaulipas, Mexico
- Canadaâ"United States border
- Sault Ste. Marie, Michigan and Sault Ste. Marie, Ontario
- Detroit, Michigan and Windsor, Ontario
- Niagara Falls, New York and Niagara Falls, Ontario
- Buffalo, New York and Fort Erie, Ontario
South America
- Argentina
- Carmen de Patagones and Viedma
- Paraná, Entre RÃos and Santa Fe
- Brazil
- Juazeiro and Petrolina
- Olinda and Recife
- Vila Velha and Vitória
- Chile
- Concepción and Talcahuano
- Coquimbo and La Serena
- Valparaiso and Viña del Mar
- Peru
- Callao and Lima
- Venezuela
- Guarenas and Guatire
- Acarigua and Araure
International
Examples, sharing names or similar names, across an international border include:
- ChuÃ, Brazil; Chuy, Uruguay
- Niagara Falls, Ontario, Canada; Niagara Falls, New York, United States
- North Portal, Saskatchewan, Canada; Portal, North Dakota, United States
- Sault Ste. Marie, Ontario, Canada; Sault Ste. Marie, Michigan, United States
- Boquillas del Carmen, Coahuila, Mexico; Boquillas, Texas, United States
- Naco, Sonora, Mexico; Naco, Arizona, United States
- Nogales, Sonora, Mexico; Nogales, Arizona, United States
- Nuevo Laredo, Tamaulipas, Mexico; Laredo, Texas, United States
- Nuevo Progreso, RÃo Bravo, Tamaulipas, Mexico; Progreso, Texas, United States
- San Luis RÃo Colorado, Sonora, Mexico; San Luis, Arizona, United States
- Tecate, Baja California, Mexico; Tecate, California, United States
- Calexico, California; Mexicali, Baja California â" see Calexicoâ"Mexicali
Pairs with unrelated names
- San Diego and Tijuana â" see San Diegoâ"Tijuana
- Detroit, Michigan and Windsor, Ontario â" see Detroitâ"Windsor
- Douglas, Arizona and Agua Prieta, Sonora
- Brownsville, Texas and Matamoros, Tamaulipas â" see Matamorosâ"Brownsville Metropolitan Area
- Eagle Pass, Texas and Piedras Negras, Coahuila
- Del Rio, Texas and Ciudad Acuña, Coahuila
- Presidio, Texas and Manuel Ojinaga, Chihuahua
- El Paso, Texas and Ciudad Juárez, Chihuahua â" see El Pasoâ"Juárez
Historic
- Brooklyn, New York and New York City - until incorporation as a single city in 1898 - as noted in "The New Colossus", inscribed on a plaque at the Statue of Liberty.
- Lloydminster, Alberta/Saskatchewan
- Thunder Bay, Ontario (formed by the amalgamation of Fort William and Port Arthur, Ontario in 1970)
Asia
Current
- Dhaka and Gazipur, Bangladesh
- Guangzhou and Foshan, People's Republic of China
- Macau and Zhuhai, People's Republic of China
- Ahmedabad and Gandhinagar, India
- Allahabad and Naini, India
- Cuttack and Bhubaneswar, India
- Munger and Jamalpur, India
- Durg and Bhilai, India
- Hubli and Dharwad, India
- Hyderabad and Secunderabad, Telangana, India
- Vijayawada and Amaravati, Andhra Pradesh, India
- Kankroli and Rajsamand, India
- Kochi and Ernakulam, India
- Kolkata and Howrah, India
- Mumbai and Navi Mumbai, India
- Pune and Pimpri-Chinchwad, India
- Harihar and Davangere, Karnataka, India
- Jalpaiguri and Siliguri, West Bengal, India
- Asansol and Durgapur, West Bengal, India
- Shivamoga and Bhadravati, Karnataka, India
- Ranchi and Hatia, India
- Tiruchirappalli and Srirangam, Tamil Nadu, India
- Tirunelveli and Palayamkottai, Tamil Nadu, India
- Seleucia and Ctesiphon, Iraq
- Tel Aviv and Jaffa, Israel
- Okayama and Kurashiki, Japan
- Tsukuba and Tsuchiura, Japan
- Nasushiobara and Otawara, Japan
- Kamisu and Kashima, Japan
- Beirut and Jounieh, Lebanon
- Kathmandu, Patan and Bhaktapur, Nepal
- Bharatpur and Narayangarh, Nepal
- Rawalpindi and Islamabad, Pakistan
- Jhelum and Sarai Alamgir, Pakistan
- Ramallah and al-Bireh, Palestine
- Dipolog and Dapitan, Philippines
- Taipei and New Taipei, Republic of China (Taiwan)
- Dammam and Khobar, Saudi Arabia
- Seoul and Incheon, South Korea
- Bangkok and Nonthaburi, Thailand
- Chiang Mai and Lamphun, Thailand
- Songkhla and Hatyai, Thailand
Historic
- Chirala-Perala, India
- Victoria and Kowloon, colonial Hong Kong - although, in both colonial Hong Kong and the Hong Kong Special Administrative Region, Victoria is the only city recognised by law; they were widely considered to be separate cities until at least the mid-1970s
- Saigon and Cholon, merged into Saigon-Cholon, now Ho Chi Minh City.
- Wuhan (merger of Wuchang, Hankou, Hanyang)
Europe
Current
- Aalborg and Nørresundby, Denmark
- Bournemouth and Poole, England
- Brighton and Hove, England
- Chatham and Rochester, England
- Leeds and Bradford, England
- Manchester and Salford, England
- Newcastle-upon-Tyne and Gateshead, England
- Porto and Vila Nova de Gaia, Portugal
- Póvoa de Varzim and Vila do Conde, Portugal
- Ludwigshafen and Mannheim, Germany
- Mainz and Wiesbaden, Germany
- Ulm and Neu-Ulm, Germany
- Sindelfingen and Böblingen, Germany
- Frankfurt and Offenbach, Germany
- Nuremberg and Fuerth, Germany
- Rotterdam and The Hague, The Netherlands
- Fredrikstad and Sarpsborg, Norway
- Porsgrunn and Skien, Norway
- Sandnes and Stavanger, Norway
- SÅupsk and Ustka, Poland
- Novi Sad and Petrovaradin, Serbia
- Zemun and New Belgrade, Serbia
- Alcobendas and San Sebastián de los Reyes, Spain
- Santa Cruz de Tenerife and San Cristóbal de la Laguna, Spain
- Elda and Petrer, Spain
- Gothenburg and Mölndal, Sweden
- Jönköping and Huskvarna, Sweden
- Athens and Piraeus, Greece
International
- Strasbourg, France and Kehl, Germany
- Frankfurt (Oder), Germany and SÅubice, Poland
- Bad Radkersburg, Austria and Gornja Radgona, Slovenia
- Comines, Belgium and Comines, France
- Mouscron, Belgium and Tourcoing, France
- Wervik, Belgium and Wervicq-Sud, France
- TÄÅ¡Ãn, Czech Republic and Cieszyn, Poland
- Copenhagen, Denmark and Malmö, Sweden
- Narva, Estonia and Ivangorod, Russia
- Valga, Estonia and Valka, Latvia
- Tornio, Finland and Haparanda, Sweden
- Hendaye, France and Irun, Spain
- Görlitz, Germany and Zgorzelec, Poland
- Guben, Germany and Gubin, Poland
- Heringsdorf, Germany and ÅwinoujÅcie, Poland
- Gorizia, Italy and Nova Gorica, Slovenia
- Kerkrade, The Netherlands and Herzogenrath, Germany
- Komárno, Slovakia and Komárom, Hungary
Historic
- City of London and City of Westminster, England. Absorbed into London.
- Buda and Pest. United into Budapest.
- Barmen and Elberfeld, Germany. United into Wuppertal.
- Bielsko and BiaÅa, Poland. United into Bielsko-BiaÅa.
- Knokke and Heist-aan-Zee. United into Knokke-Heist.
- Gradec and Kaptol. United into Zagreb.
Oceania
- Albury and Wodonga, Australia
- Canberra and Queanbeyan, Australia
- Gold Coast and Tweed Heads, Australia
- Forster and Tuncurry, Australia
- Harden and Murrumburrah, Australia
- Kalgoorlie and Boulder, Australia
- Napier and Hastings, New Zealand
- Perth and Fremantle, Australia
- Townsville and Thuringowa, Australia
- Parramatta and Sydney, Australia
Tri-cities
- Brisbane; Logan; Ipswich, Queensland Australia
- Chandigarh; Mohali; and Panchkula, India
- Stockholm; Solna; and Sundbyberg, Sweden
- San Jose; San Francisco; and Oakland, California
- New York, New York; Newark; and Jersey City, New Jersey
- GdaÅsk; Gdynia; and Sopot, Poland
- Greensboro; Winston-Salem; and High Point, North Carolina, the cities' collective metropolitan area is often called the Piedmont Triad
- Raleigh; Durham; and Chapel Hill, North Carolina, the cities' collective metropolitan area is often called the Research Triangle
- Dallas; Fort Worth; and Arlington, Texas
- Warangal; Hanamkonda; Kazipet, India
- Pasco; Richland; and Kennewick, Washington
- Dubai; Sharjah; and Ajman, United Arab Emirates
- Kitchener; Waterloo; and Cambridge, Ontario, the cities' collective metropolitan area is often called the Kitchener-Waterloo or simply K-W
- Bay City; Saginaw; and Midland, Michigan, the cities' collective metropolitan area is often called Saginaw Valley and the MBS Regions
- Temiskaming Shores, Ontario, Canada - Amalgamated the former municipalities of Cobalt, Haileybury and New Liskeard
Quad cities
- In North Carolina, the Unifour: Hickory, Lenoir, Morganton and Alexander County
- Allentown/Bethlehem, Pennsylvania and Easton, Pennsylvania/Phillipsburg, New Jersey; the collective area is often called the Lehigh Valley
- Quad Cities of Davenport and Bettendorf, Iowa, and Rock Island and Moline, Illinois. It also includes a fifth member, East Moline, Illinois.
- The Florence-Muscle Shoals Metropolitan Area in Alabama is locally referred to as "the Quad Cities", with Florence, Muscle Shoals, Sheffield, and Tuscumbia. Formerly, when Muscle Shoals was a mere village, this region was known a "Tri-Cities", Alabama. Actually, they are all incorporated as towns except for Florence.
- The Quad Cities of Minnesota consist of Virginia, Eveleth, Gilbert, and Mountain Iron.
- The cities of Pullman, Washington, Moscow, Idaho, Clarkston, Washington, and Lewiston, Idaho have marketed themselves as "Quad Cities."
- Pattaya-Chonburi Metropolitan Area consists of the City of Pattaya, Town of Chonburi, Portal town of Laem Chabang and Town of Sattahip on the west coast of Chonburi Province, Thailand
More than four cities
- In the US state of Virginia: Norfolk; Chesapeake; Hampton; Newport News; Portsmouth; Suffolk; and Virginia Beach, the cities' collective metropolitan area is often called Hampton Roads
- Ruhr district (Germany): consisting of Dortmund, Essen, Duisburg, Bochum, Oberhausen, Mühlheim, Bottrop, Gelsenkirchen and Herne in its core.
Examples of cities formed by amalgamation
Asia
- Delhi, India: What used to be Old Delhi, New Delhi, and a collection of smaller villages has now grown into the current megalopolis that we see today, also known as the National Capital Region (NCR)
- Lahore, the second largest city of Pakistan, has, as of 2013, grown out so much that small towns by this giant city, such as Shahdara, have been absorbed in its city limits.
- Wuhan in China consists of the towns of Wuchang, Hankou, and Hanyang in Hubei Province.
- Islamabad, the capital city of Pakistan, has been expanded to include smaller towns including Rawat in its territory.
- Bangkok, the capital and largest city of Thailand, was created in 1971, when the previous Bangkok province (Phra Nakhon) was merged with Thonburi province.
- Fukuoka in Japan, a city of 1.4 million people, formerly the twin cities of Hakata and Fukuoka until the late 19th century.
- Saitama in Japan, a city of 1.2 million people, created in 2001 by the merger of the cities of Urawa, Omiya, Yono, and later Iwatsuki. Urawa and Omiya could formerly have been considered twin cities.
- Kitakyushu in Japan, a city of 900,000 people, created in 1963 by the merger of Yahata, Kokura, Moji, Wakamatsu, and Tobata. Yahata and Kokura had formerly been major cities in their own right.
- The cities of Saigon and Cholon merged in 1931 to form a single city named Saigon-Cholon; in 1956, the name Cholon was dropped and the city became known as Saigon (now Ho Chi Minh City).
Europe
- London grew from its cores in the City of London and the City of Westminster to encompass many other towns and villages within neighbouring counties and absorbed almost the whole of Middlesex county.
- Budapest is the amalgamation of Buda, Pest and Ã"buda.
- Berlin (Berlin and Cölln), in Germany
- Duisburg (Duisburg and Hamborn, 1929â"1935 called Duisburg-Hamborn), in North Rhine-Westphalia, Germany
- Wuppertal (Barmen and Elberfeld), in North Rhine-Westphalia, Germany
- Manchester and the city of Salford, England in the Metropolitan County of Greater Manchester (formerly in Lancashire).
- Stoke-on-Trent was created in 1910 from the towns of Burslem, Hanley, Tunstall, Longton, Fenton and Stoke, taking its name from the latter. Neighbouring Newcastle-under-Lyme remains a separate town.
- Eindhoven merged with five neighbouring municipalities (Woensel, Tongelre, Stratum, Gestel en Blaarthem and Strijp) into the new Groot-Eindhoven ("Greater Eindhoven") in 1920. The prefix "Groot-" was later dropped.
- Madrid evolved by absorption of other towns (like Tetuán de las Victorias, Vallecas, ChamartÃn de la Rosa or Aravaca)
North America
- Richmond (Richmond and Manchester) in central Virginia
- Cleveland (Cleveland and Ohio City) in Ohio
- Minneapolis. St. Anthony (not to be confused with St. Anthony Village, a modern city which is a suburb) was a twin city to Minneapolis in the two cities' youth. Minneapolis annexed St. Anthony in the late 1800s.
- New York City (five boroughs, historically especially between Manhattan and Brooklyn)
- Jersey City, New Jersey, was incorporated in 1820, and slowly grew by annexing surrounding municipalities: Van Vorst Twp. (1851), Bergen City (1869), Hudson City (1869), Bergen Twp. (1869) and finally Greenville Twp. (1873).
- Fremont, California was formed in 1956 by the combination of the five towns of Centerville, Irvington, Niles, Mission San Jose, and Warm Springs, California. The town of Newark has always refused to merge into Fremont, and Newark is completely surrounded by Fremont.
- What is now the city of Winston-Salem, North Carolina was once two separate towns called Winston and Salem that were combined into one.
- Ottawa, Ontario, was given its large area by the amalgamation in 2001 of the old City of Ottawa, the suburbs of Nepean, Kanata, Gloucester, Rockcliffe Park, Vanier and Cumberland, Orleans, and the rural townships of West Carleton, Osgoode, Rideau, and Goulbourn
- Gatineau, Quebec, formed by the amalgamation of the old City of Gatineau, City of Hull, City of Aylmer, City of Buckingham and the Municipality of Masson-Angers all facing the City of Ottawa, Ontario from the north shore of the Ottawa River.
- Toronto formed by an amalgamation of the Old Toronto with East York, Etobicoke, North York, Scarborough and York, which were themselves products of earlier amalgamations.
- Thunder Bay, Ontario (Fort William and Port Arthur).
- Lloydminster, Canada, on the Saskatchewan-Alberta border, was formed as a single entity in 1903, when both future provinces were part of the Northwest Territories, but was divided into two separate entities in 1905 because the border between the newly created provinces bisected the community. In 1930, the two towns were reunited as a single town under the shared jurisdiction of both provinces, and Lloydminster was reincorporated as a single city in 1958.
- Halifax and Dartmouth (Canada) were forcibly merged in 1996 along with Bedford and Halifax County to create the Halifax Regional Municipality.
- Saguenay, Quebec (Chicoutimi, Jonquière, et al.)
- Bellingham, Washington was formed from four cities, Fairhaven, Sehome, Bellingham and Whatcom.
- Lincoln City, Oregon was formed in 1965 by merging the extant seaside towns of Oceanlake, Delake, and Taft, with the adjoining unincorporated areas of Nelscott and Cutler City.
- Pittsburgh annexed Allegheny City, which is now the quarter of the city that lies north of the Allegheny and Ohio rivers. Also annexed was Birmingham, now referred to as the "South Side".
- Bethlehem, Pennsylvania, which absorbed the cities of South Bethlehem, and West Bethlehem. The former Bethlehem and South Bethlehem are situated in Northampton County, and West Bethlehem is in Lehigh County. As a result, present-day Bethlehem straddles the county line.
- Montreal, Quebec, was merged with the other 27 communities on the Island of Montreal by an act in the Quebec Parliament in 2002. Following a change in the provincial government, several communities later voted via referendum to de-merge and there are now a total of 15, leaving Montreal merged with the other 12.
- Kingston, Ontario was amalgamated in 1998 with the neighboring Kingston and Pittsburgh Townships.
- Winnipeg, Manitoba amalgamated with 12 surrounding municipalities and its metropolitan corporation in 1971 under what was referred to as unicity reforms in local government restructuring.
- Park Hills, Missouri was formed in 1994 by a four-way municipal merger involving the cities of Flat River, Elvins, and Esther, plus the village of Rivermines.
- Helena-West Helena, Arkansas was formed in 2006 by the merger of the previous cities of Helena and West Helena.
- Greater Sudbury, Ontario, was formed in 2001 by the amalgamation of the former Regional Municipality of Sudbury, comprising the municipalities of Sudbury, Nickel Centre, Valley East, Capreol, Rayside-Balfour, Onaping Falls and Walden, plus a number of previously unamalgamated townships. The amalgamation made it the most populous city in the Northern Ontario region.
- Boston, Massachusetts is made up of the former towns of Boston, Dorchester, Brighton, Roxbury, Charlestown, and Hyde Park.
- Port Alberni, British Columbia was formed in 1967 when Alberni and Port Alberni, merged to become one city.
Fictional twin cities
- Gotham City (the home of Batman) and Metropolis (the home of Superman) have sometimes been presented as twin cities, mainly in 1970s and 1980s stories by DC Comics. In stories presenting them as twin cities, Gotham City and Metropolis are located on opposite sides of a large bay (identified as Delaware Bay in 1990's The Atlas of the DC Universe), with both cities linked by the Metro-Narrows Bridge, a suspension bridge resembling New York City's Verrazano-Narrows Bridge.
- Central City and Keystone City, from the current Flash comics, are shown as twin cities. Before the 1985-86 miniseries Crisis on Infinite Earths, Central and Keystone are presented as located in the same space but on different parallel Earths.
- Their real-life equivalents might possibly be St. Joseph, Missouri and either Elwood or Wathena in Kansas.
- Ankh-Morpork, from Terry Pratchett's Discworld novels, is referred to as "the twin cities of proud Ankh and pestilent Morpork"
- Duckburg and St. Canard were depicted in the cartoon Darkwing Duck as sister cities connected by a bridge, very similar to Oakland and San Francisco.
See also
- Divided cities
- United cities
- Cross-border town naming
- Megacity
- Sister cities
- List of metropolitan areas that overlap multiple countries
- List of twin towns and sister cities
- Global city
- Ecumenopolis
- Metropolis
- Megalopolis