The remains of the roman Castle can be visited
Roman Castle Robern

The Roman Small Fort Robern, also known as Hönehaus or Hönenhaus, was a Roman border fortification on the older Odenwald line of the Neckar-Odenwald Limes. It is located in the municipality of Fahrenbach in the Baden Neckar-Odenwald district.
History+
In May 1893, the Small Fort Robern was archaeologically investigated and documented by the Imperial Limes Commission under the direction of Karl Schumacher. The excavations revealed a fortification of about 400 square meters, which had previously been mistakenly considered a watchtower. It was a two-gated stone fort with an approximately square ground plan of 20 meters per side. The red sandstone enclosure had strongly rounded corners and a wall thickness of 95 to 104 cm. The main entrance was on the east side facing the Limes, with a second, smaller gate on the west side.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:200910260951MEZ_KK_Robern_06.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: 49.4664, 9.1599