Burg Wolkenstein, Medieval castle ruins in Wörschach, Austria.

Burg Wolkenstein is a ruined hilltop castle east above the entrance to the Wörschachklamm in Wörschach, Austria. Its core is the surviving wall fragment of the bergfried on the hill's highest point, later enclosed by a ring wall with a cistern. The outer bailey had a drawbridge, and the castle was the second largest fortified castle in Styria after Riegersburg.

Wolkenstein was first mentioned in 1099 in connection with Ulrich von Wolkenstein. Between 1050 and 1100 it was enlarged into a ring castle with a bailey and drawbridge to house the regional court, which gave the district its name until 1800. Pledged to Hanns Hofmann in 1524, it passed to Admont Abbey, was deemed uninhabitable by 1630, and was fully ruined by 1850.

The name Wolkenstein refers to its perch in the clouds and mountains of the region. Today visitors can see how the ruins shaped the Enns Valley landscape and serve as a reminder of medieval lordship.

A marked path leads from the village up to the ruins and takes about 15 minutes on foot along steep terrain. Sturdy footwear is recommended as the trail can be slippery when wet.

The castle was the second largest fortified castle in Styria after Riegersburg, and the largest in the Enns Valley. Its name gave the district of Liezen its political centre, called "Landgericht Wolkenstein" until 1800. The castle club Wolkenstein, with about 200 members based in Wörschach, cleared the site and made the ruin walkable again.