I haven’t been here (yet).
Hanseatic Town of Visby
A former Viking site on the island of Gotland, Visby was the main centre of the Hanseatic League in the Baltic from the 12th to the 14th century. Its 13th-century ramparts and more than 200 warehouses and wealthy merchants' dwellings from the same period make it the best-preserved fortified commercial city in northern Europe. [source]