The roman Watchtower can be visited
Roman Watchtower 13/45

The Upper Germanic-Rhaetian Limes, with a length of 550 km, from Eining near Regensburg to Rheinbrohl on the Rhine, is the largest archaeological monument in Germany and has been recognized by UNESCO as a World Heritage Site. Limes (Latin: border path/wall) refers to the border fortifications of the Roman Empire, which were erected towards the end of the 1st century AD.
This border was monitored by more than 900 towers, which were built in timber construction during the initial phase, starting around 80 AD. Stone towers followed, which were plastered from 150 AD onwards. Excavations have shown that the white plaster often had cracked joints, which were painted in terracotta. This created the impression of beautiful ashlar masonry.
At this location, the RLK discovered two stone towers and an older timber tower ditch. The finding is unique along this stretch. The timber tower, lying almost exactly in a north-south direction, stood ten meters behind the later erected Rhaetian wall.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 49.1123, 10.6782