- Currently home to the Ostrava Museum (since 1931), and the original offices of the municipal authorities. It is the oldest surviving building from the original historical city centre, and the first written document of city (dating from 1539) is housed here. The tower has had an astronomical clock since as early as the 16th century. In 1737 a new Baroque square clock tower was built (designed by Martin Keller from Potzendorf). In 1835 an extension was added to the first floor (designed by Gotsche), and in 1859 an extension was also added to the second floor (by František Boehm).