The remains of the castle can be visited
Hohenberg Castle

Hohenberg Castle, also known as the Upper Castle, is a ruined hilltop castle above Horb am Neckar. Once an important part of the town's fortifications, it is still of historical significance.
History+
Around the year 1300, Hohenberg Castle, originally called the "Upper Castle," was built at the highest point of Horb am Neckar. It served as an integral part of the urban defense system. Of the complex, the keep, known as the Schurkenturm, remains today, complemented by some wall remnants and the castle garden. In the 18th and 19th centuries, the Schurkenturm was used as a prison before finding a new function as the club house of the Swabian Alb Association from 1973 onwards.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: https://commons.wikimedia.org/wiki/File:HorbSchurkenturm.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: 48.4451, 8.6872