Charles Bridge is a medieval stone arch bridge that crosses the Vltava river in Prague, Czech Republic. Its construction started in 1357 under the auspices of King Charles IV, and finished in the early 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 Stone Bridge or Prague Bridge, but has been referred to as "Charles Bridge" since 1870.
As the only means of crossing the river Vltava until 1841, Charles Bridge was the most important connection between Prague Castle and the city's Old Town and adjacent areas. This land connection made Prague important as a trade route between Eastern and Western Europe.
A UNESCO World Heritage site, the bridge is 516 metres long and nearly 10 metres wide. Following the example of the Stone Bridge in Regensburg, it was built as a bow bridge with 16 arches shielded by ice guards. It is protected by three bridge towers, two on the Lesser Quarter side and one on the Old Town side, the Old Town Bridge Tower.