Lotrščak was one of the four medieval towers in the wall around Gradec, the old fortified Upper Town. Its name comes from campana latrunculorum — the thieves' bell, which rang every evening to warn citizens to come home before the gates closed. The tower has been rebuilt repeatedly; the current form is mostly 17th-century with a 19th-century crown.
The reason to climb it is twofold: the panoramic view from the top, which takes in the whole of the Lower Town and across to the Cathedral; and the noon cannon, the Grič Cannon, which has been fired from the top of the tower every day at noon since 1877. The shot is loud — locals say it warns the cathedral bells when to ring. There is a modest entrance fee for the climb.