Burg Kaltenstein, Medieval castle ruins in Röhrnbach, Germany

Burg Kaltenstein is a ruined hilltop castle on the 502-meter Urleinsberg above Röhrnbach. Its surviving feature is a square residential tower (Bergfried) with 11-meter sides and 1.8-meter-thick rubble-stone walls, standing about 15 meters high with four storeys and a pyramid roof. The lower masonry is medieval, the upper parts date from the 16th century. Remains of a ring wall, rampart and ditch lie beside it.

The castle received construction rights from the Bishopric of Passau in 1389 to protect the Golden Path, a major trade route between Bavaria and Bohemia. The tower was built during this period as a defensive structure and remains today as evidence of this medieval fortification era.

The name Kaltenstein refers to the rock spur on the Urleinsberg. From 1414 the castle was managed by appointed Pfleger (caretakers) such as the Häringer and Leutfaringer families, who administered the Hochstift Passau's holdings from here. After 1699 the prince-bishops used the site as a hunting lodge. The tower is now a privately owned residence and cannot be visited.

The castle can be viewed from outside and is reachable by hiking trails that pass through the area. Since the structure is privately owned, the interior is not open to visitors and you should respect the grounds when approaching the site.

The tower's lower storeys keep medieval rubble-stone masonry, while the upper fabric dates from the 16th century. Its footprint measures 11 metres per side with walls 1.8 metres thick, and the entrance sits about 2 metres above ground. The tower has been privately owned since 1966, restored and converted into a dwelling in 1975, and cannot be visited inside.