Not far from Český Dub you can come across an extraordinary geological formation - remnants of a prepared basalt dike.
This reservation was established to protect of ingenuous dendroflora characteristics for Lusatian mountains.
The Dutý Kámen nature preserve is located to the east from Cvikov. The noteworthy geological phenomenon - in English: Hollow Rock, is sandstone decomposed into unusual tiny columns. The little columns in a fan-like arrangement are 2 - 5 cm wide and up to 3 m high. The phenomenon is best visible from the 2.5-metre high rocky gnarl nearly in the middle of the ridge.
Nature preserve Babylon was established for purpose to protect rocky sandstone towns, which are wooded by fine type of pine with high and straight logs.
Nature preserve Pekelský Důl serves to protect of quaggy humid meadow with mass occurrence of endangered species of wetland´s fauna and flora.