Castelldefels, Spain and Wuxi's Binhu district signed to become sister cities on November 11, 2010.

Castelldefels became a sister city with the Wuxi Binhu District on September13, 2010. Castelldefels is located in the Catalan area and close to Barcelona with an area of 12 square kilometers and a population of 62,000, and per capita of greening area reaches 62 square meters. Castelldefels is a tourist center and economically diverse city, 73.2% of its population take part in the service industries of trading, entertainment, catering and commercial services.