The Princes' House is affectionately called the "Pearl of the Rococo Period". It was previously used as a summer house and was given its present name when the sons of the last German Emperor, William II were taught in this building. After several years of restoration, it is now again open to the public. The "Uhrenhaus" now contains the information centre for the Holstein Switzerland Nature Park. The former imperial swimming pool is now a cultural forum, which is available for events and exhibitions. Evidence of the imperial era is still visible in many parts of Plon. For example, there is on the Princes' Island, a thatched pavilion, from where there is a view of the Great Plön Lake - this was a favourite haunt of the Empress. In the chapel at the Old Cemetery is an altar donated by Empress Augusta Victoria.