Salesiova výšina, Natural monument in Osek, Czech Republic.

Salesiova výšina is a rock formation and natural monument near Osek, rising to 422 metres as the highest point of the Mostecká pánev geomorphological unit. Its quartzite blocks were deposited as alluvium by a Tertiary river; a simple viewing point on the summit now survives only as a torso.

Czech authorities designated this site as a protected natural monument in 1986 based on its geological importance. The protection status recognized the scientific value of the rock formations and their prehistoric origins.

The name recalls Salesius Krügner, abbot of Osek monastery from 1834 to 1842 and a keen admirer of the Krušné hory nature. A simple viewing platform with a gloriette once stood on the summit; only its torso remains today.

You can reach the site by following marked hiking paths from Osek město railway station or from the local swimming facility, with parking available at both starting points. The trails are straightforward to navigate and the area is well signed.

The quartzite blocks are alluvial deposits of a Tertiary river that emptied into the North Bohemian coal basin, and the freshwater mussel shells of the genus Unio left in them are visible as imprints on the stone. Collecting fossils is forbidden here.