The tower was built as a part of the bridge and it was also an important part of the Old Town’s fortification. The tower also served as a sort of triumphal arch during the coronation rides. The tower was built by Petr Parléř and his workshop in the late 14th century. The tower is 47 meters high and, similar to the bridge, it is made out of sandstone blocks and the roof is made of slate. The east side of the tower is richly decorated with symbols and statues that celebrate the power of the royal family of Luxembourg. The tiny cantilever plastics are placed at the lowest part, just above the arch of the bridge. Above them there are symbols of the countries where the Luxembourg family ruled in the time of Charles IV). The three statues are, from the left, Charles IV, St. Vitus, and Charles’s son Václav IV. Above them is a sign of St. Wenceslaus’ eagle and the floor above are St. Sigmund and St. Adalbert. In its time the tower was used as a jail for debtors. Today, it houses an interesting exposition about the astronomical and astrological circumstances of the origin of Charles Bridge. At the west side of the tower there is a stone plaque with a Latin inscription that resembles the heroic defence of the Old Town in 1848. The citizens of Prague defended the city against the Swedish army that occupied The Prague Castle and the Lesser Town at the end of the Thirty Years’ War. Nevertheless, the Swedish army took the valuable art collections from the Prague Castle.