Kluk, Mountain summit in Šumavské podhůří, Czech Republic.

Kluk is a 741 m summit in the Prachatice Highlands, part of the Šumava foothills, 12 km southwest of České Budějovice. A large granulite rock rises at the top, with a small iron cross and, since about 2020, a non-working hand pump; a transmitter stands north of the summit.

Fragments of La Tène pottery found on Kluk suggest its summit rock may have served as a lookout for the Celtic oppidum of Třísov, 4.4 km to the southeast. The mountain's first written mention dates from 1375, when it was recorded as Kluk; in German it was called Bubenstein.

The name Kluk may come from a Celtic word for "great rock", or from an Old Czech term for cleared, treeless ground. Legends tell of a boy (kluk) turned to stone on the summit, or of a guardian spirit in the mountain who appears as a small boy and can raise deadly storms.

Marked hiking trails lead to the summit, and visitor information with maps is available at nearby towns. Proper footwear and clothing suitable for changing mountain weather will make the visit more comfortable.

The summit rock is also called K2 of the Blanský les, though it is not the second-highest peak but rather the second most notable. Fragments of La Tène pottery found here suggest the rock may have served as a lookout for the Celtic oppidum of Třísov, 4.4 km to the southeast.