Burgruine Griffen, Medieval castle ruin in Griffen, Austria.

Burgruine Griffen is a castle ruin on the 130-meter-high limestone Griffner Schlossberg above Griffen in Carinthia. Its walled area covered about 4,000 square meters. A lightning strike destroyed one of its towers in 1659, and the dilapidated roofs were torn down around 1840. A hiking trail now leads up the hill to the ruin.

A bishop from Bamberg ordered the castle built between 1124 and 1146, and an emperor later documented it as an important fortification. Over the centuries, the structure was repeatedly rebuilt and expanded to meet changing military requirements.

The name Grivena appears in a 1160 deed of Emperor Friedrich I, and the Slovene name Grad Grebinj is still used for the site. The castle held blood jurisdiction until 1425, the right to try capital cases in the surrounding area. A hiking trail now leads up the Schlossberg to the ruin.

The ruins are reached by a steep stairway starting near the church in Griffen, with parking available at the base of the hill. The climb is demanding and requires sturdy footwear and a moderate level of fitness.

Beneath the ruins lies a dripstone cave about 485 meters long, discovered by chance during World War II and later opened to visitors. Today hikers can explore both attractions in one location, gaining a double perspective on the geology and history of the area.