The Charles Bridge is a famous historic bridge that crosses the Vltava river in Prague. Its construction started in 1357 under the auspices of King Charles IV, and finished in the beginning of the 15th century. The bridge replaced the old Judith Bridge built 1158–1172 that had been badly damaged by a flood in 1342. This new bridge was originally called the Stone Bridge (Kamenný most) or the Prague Bridge (Pražský most) but has been the 'Charles Bridge' since 1870. As the only means of crossing the river Vltava until 1841, the Charles Bridge was the most important connection between Prague Castle and the city's Old Town and adjacent areas. This 'solid-land' connection made Prague important as a trade route between Eastern and Western Europe.
The bridge is 621 metres long and nearly 10 metres wide, resting on 16 arches shielded by ice guards. It is protected by three bridge towers, two of them on the Lesser Quarter side and the third one on the Old Town side. The Old Town bridge tower is often considered to be one of the most astonishing civil gothic-style buildings in the world. The bridge is decorated by a continuous alley of 30 statues and statuaries, most of them baroque-style, originally erected around 1700 but now all replaced by replicas.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.