Rheinfelden-Pferrichgraben

Rheinfelden-Pferrichgraben is a late Roman watchtower in Rheinfelden, built during Emperor Valentinian’s fourth-century reign. Its rhomboid ground plan marks an unusual example of Roman military architecture. The tower formed part of a surveillance network stretching about 150 kilometres along the Rhine, the Roman Empire’s frontier with Germanic tribes. About fifty watchtowers and military installations once occupied this Rhine corridor. The tower stood about 25 metres above the Rhine. Originally six to eight metres high, it allowed visual contact with neighbouring towers near Stein and Heimenholz. A northern ditch and a later lime kiln also belong to the archaeological record. Pastor Sebastian Burkart discovered the ruins in 1900, and later work exposed the foundations and sealed the wall tops against water. Conservation work continued, with a major restoration completed in 2017. During restoration, archaeology students documented the masonry, while mortar samples supported research into dating ancient walls. The site connects Roman border defence with archaeological education and research.