The medieval castle situated on a rocky peak and surrounded on three sides by the river Ohře has been already founded in the 12th century. Together with the city under the castle it became an important support for the Czech kings and a centre of the region’s administration. Many used to call the fortified castle and the town “the key to the Czech Kingdom”. During the medieval era it was claimed that whoever conquered Loket would conquer the whole kingdom. The castle served as a residence of the Přemyslid and Luxembourg rulers. During the Hussite wars it was gaged by aristocratic families and in 1598 it became the property of the city of Loket. Part of the castle was used as a prison from the beginning of the 19th century until 1948, in addition, in 1907 a museum was established there as well. The entire castle was open to the public in the beginning of the 1950s.