Zytglogge, Bern, Switzerland
Bern, Switzerland's unique astronomical clock became a town fixture when it was added to a medieval-era tower in the 1500s. The Zytglogge's most impressive feature is its 3,000-pound bronze bell, and also has two main clock faces and a smaller astronomical clock that tells the day of the week, time of day, date, lunar phases and even the current zodiac sign. The tower was once a jail and visitors can still pass through a small gate that was used in medieval times to allow people to enter the walled section of the city. It's all part of Bern's Old City, which has been designated a World Heritage Site by UNESCO.