Iron Tower

The Iron Tower (German: Eisenturm) is a mediaeval tower dating to the early 13th century, and modified in the 15th century, which with the Wood Tower and the Alexander Tower is one of three remaining towers from the city walls of Mainz, Germany. Its name derives from the Iron Market (Eisenmarkt), which was held in the immediate vicinity until the 19th century.

The Iron Tower served as a watchtower and gate to the city, and later as a gaol. It was badly damaged in World War II and reconstructed in the 1960s. Today it houses various organisations and arts projects and is used for art exhibitions.

Since late Roman times, the city of Mainz (then Mogontiacum) was defended by a wall with watchtowers and city gates. The first wall was built shortly before the destruction of the limes in 259/260 CE. Not long after 350, in the course of the abandonment of the Roman camp, this wall was lowered and rubble (spolia) from earlier construction used to enlarge and strengthen it. After the Romans withdrew, it was improved at various times, particularly in the Merovingian and Carolingian periods, becoming what archaeologists studying the city have called the "Roman-Carolingian" wall.

However, in 1160 the continuity of the city's defences was drastically interrupted. There was a longstanding dispute between the citizens of Mainz and their archbishop, Arnold of Selenhofen (and also with the Holy Roman Emperor Frederick Barbarossa); after the archbishop was murdered, the emperor imposed an imperial ban on the city. The city walls and towers were razed (although it is possible that on the inland side the destruction was only partial).

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