Rostock, the biggest port and shipbuilding center of the former East Germany, was founded around 1200. Of all the Hanseatic cities, the once-thriving Rostock suffered the most from the dissolution of the League in 1669. The GDR reestablished Rostock as a major port, but shipbuilding work has been cut in half since unification. Ferries from Gedser (Denmark) and Trelleborg (Sweden) come here. The population of Rostock doubles
in the summer due to Baltic cruise ships that dock in Warnemünde. The biggest local annual attraction is Hanse Sail, a week of yacht racing held in August.