Description:
The first written mention of Basel states that the Roman Emperor Valentinian had built a small fortress, a so-called munimentum, in 374 AD at Basilia to secure the Rhine frontier. Their tower is marked at Reverenzgässlein 8 with paving stones in the ground.
Finding:
The massive walls of the Munimentum were excavated in the 1960s.
Source: https://www.archaeologie.bs.ch/vermitteln/info-stellen/reverenzgaesslein-8.html