Salesiova výšina is a compact but fascinating rock formation near the town of Osek, and surprisingly, it's the highest point of the entire Most Basin geomorphological unit. At just 422 metres, it doesn't tower over the landscape, but its quartzite rock towers certainly leave an impression.

The quartzite blocks here were formed as sediments of a Tertiary-period river that once flowed into the North Bohemian coal basin. Look closely and you'll spot thousands of fossilised imprints of freshwater mussels from the genus Unio. The surrounding forest, dominated by old beech trees twisting into bizarre shapes as they grow out of the rocky ground, gives the whole area an almost fairy-tale atmosphere, especially in autumn mist or winter frost. At the summit you'll find the remains of a former lookout point once crowned with a small gloriette, offering sweeping views over the countryside.

• Osek - local educational trail, approx. 30-45 minutes, easy difficulty
• Can be combined with other historical sites along the same nature trail

• Protected as a natural monument since 1986 - climbing on the rocks is forbidden outside the designated climbing routes
• Collecting fossils is prohibited
• Leaving marked paths is not allowed
• Four climbing routes lead to the summit, the longest measuring 18 m

The hill is named after Salesius Krügner, abbot of Osek Monastery from 1834 to 1842 and a passionate lover of the Ore Mountains' nature.