Dammam and Khobar, Saudi Arabia South Korea Seoul and Incheon, South Korea Busan and Ulsan, South Korea Sejong City and Daejeon, South Korea Yangyang and Sokcho, South Korea Taiwan Taipei and New Taipei, Taiwan Thailand Bangkok and Nonthaburi, Thailand Chiang Mai and Lamphun, Thailand Songkhla and Hatyai, Thailand Vietnam Ho Chi Minh City and Binh Duong, Vietnam International Astara, Azerbaijan and Astara, Iran Dandong, China and Sinuiju, North Korea Manzhouli, China and Zabaykalsk, Russia Heihe, China and Blagoveshchensk, Russia Historic Victoria and Kowloon, colonial Hong Kongalthough, 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 Chirala-Perala, India Ise, Japan (merger of Uji, Yamada) Joetsu, Japan (merger of Takada, Naoetsu) Naha and Shuri, Okinawa, Japan, once separate cities, Shuri became integrated as a district of Naha Wuhan, China (merger of Wuchang, Hankou, Hanyang) Saigon and Cholon, Vietnam, merged into Saigon-Cholon, now Ho Chi Minh City. Europe Current Denmark Nørresundby and Aalborg, Denmark France Frejus and Saint-Raphaël, France Lyon and Villeurbanne, France Germany Frankfurt and Offenbach, Germany Ludwigshafen and Mannheim, Germany Mainz and Wiesbaden, Germany Nuremberg and Fuerth, Germany Sindelfingen and Böblingen, Germany Ulm and Neu-Ulm, Germany Ireland Ballybofey and Stranorlar, in County Donegal, Ireland are often called the Twin Towns and form the census town, Ballybofey and Stranorlar Norway Fredrikstad and Sarpsborg, Norway Porsgrunn and Skien, Norway Sandnes and Stavanger, Norway Poland Bydgoszcz and Toruń, Poland Kalisz and Ostrów Wielkopolski, Poland Portugal Porto and Vila Nova de Gaia, Portugal Póvoa de Varzim and Vila do Conde, Portugal Serbia Novi Sad and Petrovaradin, Serbia Temerin and Bački Jarak, Serbia Zemun and New Belgrade, Serbia Spain Alcobendas and San Sebastián de los Reyes, Spain Aldaia and Alaquàs, Spain Coslada and San Fernando de Henares, Spain Elda and Petrer, Spain Llombai and Catadau, Spain Santa Cruz de Tenerife and San Cristóbal de la Laguna, Spain Sweden Jönköping and Huskvarna, Sweden Ukraine Donetsk and Makiivka, Ukraine United Kingdom Bournemouth and Poole, United Kingdom Brighton and Hove, United Kingdom Chatham and Rochester, United Kingdom Chester, England and Saltney, Wales Leeds and Bradford, United Kingdom Manchester and Salford, United Kingdom Newcastle upon Tyne and Gateshead, England Liverpool and Birkenhead, England Kingston upon Hull and Grimsby, England International Austria–Slovakia border Vienna, Austria and Bratislava, Slovakia Austria–Slovenia border Bad Radkersburg, Austria and Gornja Radgona, Slovenia