Burg Kleinvernich, Water castle in Weilerswist, Germany.

Burg Kleinvernich, also called Gürtzgensburg, is the remnant of a moated castle on the Lommersumer Mühlengraben near the Erft in the Kleinvernich district of Weilerswist. It is a four-winged courtyard complex surrounded by a complete moat and is used as an agricultural estate and residence.

The site is documented in 1610 as held by the Lords of Gürtzgen, from whom the name Gürtzgensburg comes. Drawings of 1705 show a small half-timbered manor already decaying and suggest a forecourt. By the early 18th century the late Gothic castle was entirely ruined, and in 1730 it lost its right to a seat in the Landtag because it no longer met the requirements. The courtyard complex was rebuilt in 1781.

The name Gürtzgensburg recalls the Lords of Gürtzgen, recorded as owners in 1610. The site is called a Hoffeste, a fortified farmstead without knightly status, and it lost its right to sit in the Landtag in 1730 because it no longer met the requirements. The four wings still combine dwelling and farm use.

The castle functions as an active farm today, where residents maintain the historic buildings while running agricultural operations. Visitors should be respectful since this is a working property, not a museum, and much of the grounds are private.

The complex was a so-called Hoffeste, a fortified farmstead without knightly status, and it lost its right to sit in the Landtag in 1730 because it no longer met the requirements. A drawing from 1705 shows that a small half-timbered manor house had already decayed, and the present courtyard buildings date from a rebuild in 1781.