Rýzmberk Castle, Castle ruins and observation tower in Podzámčí, Czech Republic.

Rýzmberk is a castle ruin with an observation tower located in Podzámčí in the Czech Republic. The site comprises Gothic stone walls and a modern tower standing at its center.

Rýzmberk was founded in the second half of the 13th century, first mentioned in 1279, by the Drslavic family to guard the Regensburg Steig through the Všeruby Pass. A fire in 1448 led to a major Gothic rebuild under the Janovský of Rýzmberk. Imperial troops under Baltasar de Marradas took it in 1620, Swedes under Generalmajor Pful sacked it in 1641, and it was abandoned after the Thirty Years' War.

The castle's German name Riesenberg, "Giant Mountain", matched its position above Kdyně. Since 1935 an open-air stage has stood on the site, and the annual Rýzmberský hradní guláš country and folklore festival is held there. The ruin also appears in George Sand's novel Consuelo.

The site has pathways leading to the ruins and observation platform that are open year-round. Wear sturdy shoes since the ground is uneven in places and there are stairs to climb.

The ruin appears in George Sand's novel Consuelo, and since 1935 an open-air stage has stood on the site; amateur theatre groups performed there first, and today the annual country and folklore festival Rýzmberský hradní guláš takes place on it.