Central Rostock’s pride and joy is the 13th-century Marienkirche, the only main Rostock church to survive WWII unscathed (although restorations are ongoing). Behind the main altar, the church’s 12m-high astrological clock was built in 1472 by Hans Düringer. At the very top of the clock is a series of doors. At noon and midnight the innermost right door opens and six of the 12 apostles march out to parade around Jesus (Judas is locked out). Zodiac symbols and moon phases feature in the centre, while the lower section has a disc that tells the exact day on which Easter falls in any given year. The replaceable discs are accurate for 130 years – the current one expires in 2017, and a new one is ready. The clock is the only one of its kind in the world still with its original mechanisms. Also note the unusually tall, organically shaped baroque organ (1770).