Chronicle
The castle stands at about 210 m above sea level on the south-facing slope of the Neckar valley, between Binau and Obrigheim, above the B 37 road. Its rock is not part of the hills: it is calcareous tufa, deposited by a strongly lime-rich, copiously flowing spring — stone that has precipitated out of water. In the Neckar valley it is a foreign body. Ludwig H. Hildebrandt describes the medieval sight as a castle on a white rock of a kind the Neckar valley does not otherwise know. Hence, probably, the name: Tahenstein, Tugstein, Duckstein, Dauchstein, in modern German Tuffstein, tufa. Legend derives it differently, from a toll chain across the Neckar that was only lowered — “gedaucht” — once payment had been made. The tower itself is built of Bunter sandstone (Buntsandstein); in 2024 the Denkmalstiftung described its walls as unrendered and about 1.70 m thick. Whether tufa was used anywhere else on the site — Naeher noted tufa masonry in 1893, Hildebrandt adds a question mark — is as unproven as the origin of the sandstone.
Source:
https://stonelight.maroncloud.de