Burg Lohmar, Former moated castle in Lohmar, Germany

Burg Lohmar is a medieval water castle in the Bergian region featuring a two-story manor house built from greywacke stone with three connected outbuildings. The complex is surrounded by moats and demonstrates the defensive layout typical of a noble residence from the Middle Ages.

The Gothic water castle was built around the middle of the 14th century by Count Dietrich II of Loos and Chiney, lord of Heinsberg, Blankenberg and Löwenburg, probably on the remains of an older noble seat. A charter of his nephew Count Godart of Loen dated 19 March 1361 shows the building was unlawful; only the friendship of the Count of Berg spared it from immediate demolition, and Godart pledged to use it solely as a dwelling and not to fortify it further. By 1400 it had passed from the von Loen family to the von Ro(i)de, who sold it on 21 May 1444 to Gerhard von Reven and Juetgin von Hatzfeld; it stayed with the von Reven until 1693 and was sold to the Contzen family in 1818.

The name Lohmar is tied to the von Loen family, who held the castle until about 1400, when it passed to the von Ro(i)de. The gate arch of the eastern wing carries the marriage coat of arms of the von Groote and Coesfeld families, owners in the early 18th century. The complex is still run as a farm.

The complex is still run as a farm and can only be viewed from the outside. It lies in the Agger valley about half a kilometre west of Lohmar town centre, outside the built-up area, directly between the river and the A3 motorway. The former moat is no longer filled with water and its north-eastern part has been filled in or built over.

The gateway arch of the east wing carries the joint coat of arms of the von Groote and Coesfeld families, owners of the castle at the start of the 18th century. The masonry bridge in front of it crosses the remains of the former moat, which is no longer filled with water and is filled in or built over in the northeast.