Museum
Martinsburg Castle

Martinsburg Castle, also known simply as Martinsburg, is an impressive castle complex in Lahnstein. Originally built in 1298 as a customs castle by the Archbishops of Mainz, it is one of the few undestroyed castles on the Middle Rhine and once served to secure important customs rights.
History+
Martinsburg Castle was constructed in the late 13th century by the Archbishops of Mainz to enforce their customs rights on the Rhine, which they had held since 1292 with royal permission. Unlike Lahneck Castle, which was situated higher up, Martinsburg was built directly on the Rhine. It is believed that a fortified structure already existed at this site in the mid-13th century. The oldest parts of the castle include a rectangular residential tower with two corner towers and the foundations of the hexagonal main tower. The current 28-meter-high keep was built around 1400.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=932
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: 50.2975, 7.6056