The remains of the Castle can be visited
Adolfseck Castle (Ruin)

The Adolfseck ruin, once a spur castle, stands on the southern edge of the Bad Schwalbach district of Adolfseck. Located on a meander core of the Aar river, it is now freely accessible.
History+
The origins of Adolfseck Castle date back to 1356, when Count Adolf I of Nassau-Wiesbaden-Idstein began its construction and received it as a fief from the Mainz Archbishop Gerlach von Nassau. Eleven years later, in 1367, Adolfseck was granted town rights. After Adolf's death in 1370, ownership passed to his son Count Walram IV, who handed the castle over to his brother Johann in 1386. When Johann became Archbishop of Mainz in 1397, the castle reverted to Adolf II, the nephew and son of the original builder. The Nassau complex served to secure the Bäderstraße and as protection against the County of Katzenelnbogen.
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: 50.1589, 8.0799