Sister city

A sister city or twin town relationship is a form of legal or social agreement between two geographically and politically distinct localities for the purpose of promoting cultural and commercial ties.[1]

Twin towns fingerpost signage in Oskarshamn, Sweden, listing these: Middelfart, Denmark; Mandal, Norway; Pärnu, Estonia; Korsholm, Finland; and Hibiscus Coast, South Africa

While there are early examples of international links between municipalities akin to what are known as sister cities or twin towns today dating back to the 9th century,[2] the modern concept was first established and adopted worldwide during World War II.[3][4]