The cluster of buildings that forms the Kaiserburg is sited on the high ground in the north-east corner of the Aldstadt. The origins of the buildings go back to 1040 – when the Fünfeckturm (Pentagonal Tower) was built. Taking full advantage of the security provided by the natural rocky outcrop, the buildings inside the Kaiserburg are quite domestic in scale and appearance.
There are several clusters of buildings. Lower down is the Kaiserstallung (Emperor’s Stables) which is now a youth hostel. The roof of this can bee seen in the topmost photograph. The most important buildings are those of the imperial palace which date from the 12th century.