The Zimmer tower is a tower in Lier, Belgium, also known as the Cornelius tower, that was originally a keep of Lier's 14th-century city fortifications. In 1930, astronomer and clockmaker Louis Zimmer (1888–1970) built the Jubilee Clock, which is displayed on the front of the tower, and consists of 12 clocks encircling a central one with 57 dials. These clocks showed time on all continents, phases of the Moon, times of tides and many other periodic phenomena.