Salesiova Uplands are a geological rarity, as they are formed by alluvium deposits from a primeval river on the site of an estuary flowing into the North Bohemia coal basin. You can see prints of freshwater clams on the rocky blocks. The rock formations are formed from quartzite that is unusually smooth and firm This area became a natural landmark in 1986 and it covers an area of 2 hectares. The Salesiova Uplands area is located on the nature trail going around Osek. There is also a yellow marked tourist route from the open air swimming pool in Osek. There is a romantic rocky labyrinth which was a popular tourist destination already in the first half of the 19th century; at that time the terrain was not covered by tall forests and the views must have been magnificent. The abbot of Osek Cloister had a simple observation point constructed there from 1834-1843 . The observation point was replaced with a romantic wooden folly, also called a summerhouse, in the 2nd half of the 19th century; unfortunately, it has not survived. Deep underneath is a mining field of a former pit called Nelson VII. 11 miners died there during a mining catastrophe. Mining stopped in 1960 and the surface equipment, including the mining towers was removed in 1972.