Rostock astronomical clock, Astronomical clock in St. Mary's Church, Rostock, Germany

The Rostock astronomical clock stands in the ambulatory of St. Mary's Church, between two pillars behind the high altar, and is eleven metres tall. It has three stacked parts: a carillon with a semicircular stage and a figure of Jesus, a clock dial of 1472 with concentric rings for the hour, zodiac and months, and a calendar valid until 2150.

A clock is recorded in St. Mary's Church as early as 1379, when the city accounts note 212.5 marks paid for a clock and its case, possibly to Nikolaus Lilienfeld. It was damaged in 1398 during rebuilding work. In 1470 the city council commissioned Nuremberg clockmaker Hans Düringer to build a new astronomical clock; in 1472 Bishop Werner von Schwerin granted forty days' indulgence to those who contributed to it. After the Reformation maintenance lapsed, and Lorenz Borchhard restored it between 1641 and 1643, rebuilding the case in late-Renaissance style; in 1710 the weight drive was replaced by a pendulum. Carl Börger and Hendricus Jansen carried out a full restoration in 1885, and a concrete wall protected the clock from bombing in early 1943, removed in 1951.

At noon, a mechanical device sends the twelve apostles through a door past a moving statue of Jesus, who blesses them before they re-enter another door. Judas goes last, does not bow, and the door closes before him, so he must wait until the next day. Four carved wooden panels of Adam and Eve, placed in the 17th century, sit atop the clock.

The clock is in the ambulatory, between two pillars behind the high altar, and stands eleven metres tall. The procession of the twelve apostles runs at noon, not at every hour. The present high altar, built in 1720, blocks the view of the clock's top from the nave.

In early 1943, fearing air raids and recalling the destruction of Lübeck's astronomical clock the year before, a concrete wall was built in front of the clock. It was removed only in 1951, and the clock suffered no significant damage.