The remains of the roman Watchtower can be visited
Roman Watchtower 12/77

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.
In 1969, the foundations of the stone tower were uncovered by the State Monuments Office of Baden-Württemberg and restored after examination by the Ostalbkreis district. Archaeologists identified three construction phases for Wp 12/77. Slightly south of the later Limes wall, a wooden watchtower, probably erected around 130 to 135 AD based on findings from the Limes Gate Dalkingen, was identified, near which remnants of the wooden Limes palisade had been preserved. Their age is quite precisely known from the timbers excavated in nearby Schwabsberg. Planck and Baatz dated their construction to the period from 161 to around 165 AD. With the end of the first tower, which may have become old and damaged, a stone tower measuring 6.5 × 5.5 meters, of which only minor remains survived, was built northwest of the wooden predecessor. The ditch-like depression running around it made it clear that this fortification once stood freely in the field. Although the oak log palisade could not be found there, the tower certainly belongs to this period.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Wp12_77_Rekonstruktion.jpg
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: 48.9158, 10.1308