The former Prince Bishop's residence was built from 1767 to 1787 as a three-winged building by J.C. Schlaun with rich figure decorations on the facades. Following destruction during the war, the outer appearance was restored true to the original. Today, the castle forms the main building of the university.

To the left of the main castle building, a small door leads into the castle garden with its stock of beautiful old trees. The botanical gardens of the university are at the rear. Three times a year an enormous fair - the Send - takes place on the Hindenburgplatz in front of the castle attracting thousands of visitors. The university's central lecture hall also lies on the Hindenburgplatz, where conferences and even concerts are frequently held.

Four times a year, during the summer months, a large flea market is held on the promenade in front of the castle, an attraction for both people inclined to buy and curious onlookers  from near and far.