Fortress Skansen Kronan, together with its twin sister Skansen Lejonet, was designed by Erik Jönsson Dahlberg, a military engineer, in order to protect the city of  Gothenburg from the Danish attacks, and completed in 1700. Upon its completion, the fortress was ready for battle and had 23 cannons, but was never attacked. In the 19th century, it was used as a prison, 20th century as a military museum, and there is a café that serves homemade pastry and ice cream.