Lotrščak Ball in Zagreb is a historic Romanesque tower, the best preserved element of the city's fortifications. Its total height is 30 meters (including 5 meters is a roof, and 6 - a metal dome). Around the dome there is an observation deck, very popular with tourists, from here you can admire the extensive city panorama. The tower was entered in the register of Croatian monuments.
Kula Lotrščak was founded in the 13th century, however, it owes its present appearance to the nineteenth-century reconstruction designed by architect Kuno Waidmann. It is a 5-storey building, the first four floors have walls that are almost two meters thick (characteristic of Romanesque buildings), the top floor was built of bricks.
A small cannon has been on the tower since the end of the 19th century, a shot is fired every day at noon at noon. The gun used today was donated to the city by the Yugoslav army in connection with the Universiade held in 1987.