Many uses and traces of everyday life at the castle can still be found today. These include the demesne (farm) on the ascent up to the fortress, which as a business enterprise had to make essentials available to the garrison.
It also provided wood, grain and hay. In addition, the castle maintained its own cemetery, its own jurisdiction, which is still apparent today from the field name "Galgenrain" (gallows slope), princely and garrison lodging, a guesthouse, a pharmacy, a blacksmith's workshop, a cooperage, wells and, of course, a well stocked weapon's arsenal.
During the Thirty Years' War (1618-1648) the worthwhile fortification of Hohentwiel became clear as the result of several failed sieges. The commandant Konrad Widerholt withstood five enemy attacks from 1635 to 1644. Widerholt, who as a citizen of Württemberg was on the Protestant side, erected a church at Hohentwiel between 1643 and 1645. In 1650 he returned the fortress Hohentwiel undamaged to the Württemberg Duke Eberhard III.
This fortification no longer helped the Hohentwiel commander when it was forced to surrender by the French General Vandamme, who stood before Hohentwiel Castle with superior Napoleonic troops in the 2nd Coalition War.
The occupation cleared the fortress, which was then ordered razed by Napoleon. In early 1801 the proud fortress was reduced to a ruin after 900 years.
With its romanticizing and historicizing interests, Hohentwiel remained significant in the 19th century. Tourism and the "Hohentwiel-Festspiele" (Hohentwiel Festival) conquered the former knight's castle. In 1941 Hohentwiel and the surrounding area were declared a nature preserve. The information center set up in 1994 in the old coach house of the demesne not only shows the visitors a model of Hohentwiel as it was in the 18th century, it also provides information on the fortress ruins with videos.