Burg Hattstein, Medieval castle ruins in Oberreifenberg, Germany.

Burg Hattstein is the remnant of a spur castle on a wooded spur north of the Sängelberg, between Schmitten and Oberreifenberg. Of the former complex, only a few remains of a shield wall and a conspicuous moat around a raised area can be seen today.

The castle originated before 1156 and is first documented through a name in regional founding papers. It played a role in local territorial history across several centuries.

The castle's name appears as "Hazechenstein" in the 1156 Walsdorf foundation charter, which names Guntramus de Hazechenstein as lord. The Hattstein knights acted as robber barons in the 14th century, raiding the Thron monastery in 1387 despite a 1379 oath. The Hattsteiner Feud (1428–1435) ended with the castle's capture in 1432 by Reifenberg, Frankfurt and Kurmainz forces.

The site is accessible via marked hiking trails from the parking area on L3025 near Angelweiher. Wear sturdy footwear and be cautious on wet terrain, as the ground is uneven.

The castle was half a fief of the Electorate of Trier, unlike the fief-free Reifenberg Castle. In 1614 Philipp Georg von Hattstein sold the fief-free half to Johann Heinrich von Reifenberg, but the price was never fully paid, and the resulting lawsuit dragged on until the Hattstein line died out in 1767.