Visby is the city in the Gotland Island of the Baltic Sea. It was one of the important centers of the Hanseatic League in the 12th - 14th centuries. The old town is surrounded by a ring wall built in the 13th century. This Kaiser Tower is one of the towers standing on its ring wall. This tower was used as a prison from the end of the 17th century until the early 19th century, and now it is used as the museum.
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(2019-01-21)