From a distance, the dome of the Zug clock tower appears blue-white but as you get closer to it, you can see the time on it. But not just the time, it also shows the month, the phase of the moon, the day of the week and whether it is a leap year or not. The tower was actually built as a way through the oldest city walls and later part of it was used as a prison as well as housing a room to keep warm by an open fire. Today the 52-metre-high tower is open to everyone, an opportunity not to be missed. After all, where else other than Zug can you get the key yourself to a city landmark.
The tower was originally built in the 13th century and heightened in 1478-1480. The current appearance dates from 1557.
References:The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.