Castra Bonna

Castra Bonna was a Roman military fort on the Rhine, built with massive stone walls and the standard construction methods of the Roman army. The preserved foundation walls and excavations reveal the rectangular layout of a typical fortress with watchtowers and residential quarters.

The fort was founded in the 1st century CE to secure the northern border of the Roman Empire against Germanic tribes. It remained occupied for over 300 years before declining in importance as Roman military presence shifted throughout the region.

The remains show how Roman soldiers and local people lived alongside each other for centuries, blending their building styles and daily practices. Visitors can still observe today how this mixing shaped the architectural character of the Rhine region.

Most of the site is not immediately visible, as large sections of the fortress lie buried beneath the modern city. The Rheinische Landesmuseum Bonn displays finds from the location and helps visitors understand what once stood there.

Sections of the original Roman walls were later incorporated into medieval fortification walls throughout the region and remain visible today. This reuse shows how Roman structures continued to shape the Rhineland long after the empire's collapse.