Alte Burg, Medieval castle ruin in Rotenhain, Germany

Alte Burg is a tower-mound castle (motte) site from the second half of the 13th century in Rotenhain. Visible are the 15 × 16 m foundation walls, a 6 m deep well, a 2–3 m wide moat and a 2 m high mound. The present building is a complete reconstruction erected from 2009 to 2012 by the local Historica association using modern materials, following the archaeologically proven ground plan.

The motte dates from the second half of the 13th century. No historical records about the castle survive, so it bears the emergency name "Alte Burg". It was occupied only briefly and was not taken by force: after abandonment it was demolished down to its foundations. Excavations from 1997 to 2000 uncovered charred stored grain, pottery shards and animal bones.

The reconstruction, built from 2009 to 2012 by the Rotenhain association "Historica" with volunteer labour and state grants, uses modern materials such as shaped blocks and concrete. Its interior, decorated with medieval motifs, is used for events. The building follows the footprint of the archaeologically attested walls, while window and door details are freely designed.

The rebuilt structure stands on the archaeologically attested 15 × 16 m footprint, with the 2–3 m-wide moat and 2 m-high mound still visible around it. The interior is used for events and is fitted out with medieval motifs, so check locally before planning a look inside.

The castle well operates using an inverted coffee filter principle with clay and sand layers to naturally purify groundwater. This filtration system shows how medieval builders treated water without modern technology.