The Lotrščak Tower (Croatian: Kula Lotrščak, pronounced [kǔːla lotřʃtʃaːk, kǔːla lotrʃtʃâːk]) is a fortified tower located in Zagreb, Croatia, in old part of town called Gradec or Gornji grad (English: Upper town). The tower, which dates to the 13th century, was built to guard the southern gate of the Gradec town wall.