Schloss Martinsburg

Lahnstein, Germany, Germany

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Schloss Martinsburg in Lahnstein, Rhineland-Palatinate, Germany, stands as a rare well-preserved lowland toll castle on the Rhine, built around 1298 by the Archbishops of Mainz to enforce customs duties after securing shares in Boppard’s imperial tolls, with its oldest parts including a 13th-century rectangular residential tower, corner towers, and foundations of a later 28-meter hexagonal keep erected circa 1400.

Expanded as part of Oberlahnstein’s town fortifications after 1324—with a moat, gated defenses, and Gothic wings added in the 14th-15th centuries, plus a Baroque southwest wing by Archbishop Franz Lothar von Schönborn between 1719-1721—it served administrative roles until Mainz lost control in 1803, avoiding destruction unlike many Rhine peers.

Today, this UNESCO Middle Rhine Valley site mixes Gothic, Renaissance, and Baroque elements, housing a carnival museum alongside apartments and offices, with its exterior park accessible to visitors.