Bridge tower should not be confused with Tower Bridge.
A bridge tower (German: Brückenturm) was a type of fortified tower built on a bridge. They were typically built in the period up to early modern times as part of a city or town wall or castle. There is usually a tower at both ends of the bridge. During the 19th century, a number of bridge towers were built in the Gothic Revival style – Tower Bridge in London is perhaps the best known example; however, many original medieval towers survive across Europe.
These towers were built in pre-medieval and medieval times to guard access to the bridge and to enable the charging of tolls on important roads crossing rivers, usually near towns and cities. The rivers were often part of the defences of these settlements. As a result, it was important from a defensive perspective that the bridges did not allow attacking enemies to break in. The bridges acted as a bulwark and often had a small drawbridge. In addition to their genuine protective and defensive functions they also played a symbolic and architectural role. Often these towers were the first public buildings that the travellers saw when approaching the city.
Sometimes, the same building served as bridge tower and bridge chapel, for example at the Krämerbrücke in Erfurt.
The high cost of such towers was usually paid for by charging tolls. The gates of bridge towers were closed at night, so that no-one could cross the bridge during silent hours.