The Twinning or Sister city concept developed in Europe following the Second World War. It was seen as a way of removing old enmities which had developed in the war years and it is now grown to such an extent that it covers not just the European mainland, where it began, but also the United Kingdom, Ireland, United States, Asia, Africa and beyond. Cork is currently twinned with six cities:

1969 Coventry , UK
1982 Rennes , France
1984 San Francisco , USA
1988 Cologne , Germany
1994 Swansea , Wales
2005 Shanghai , China

The objective of twinning is to help develop links in many areas – cultural, educational, social, tourist, technical, scientific and economic and it is hoped that the development of such links would have benefits for all communities involved.