The Rotavské varhany Nature Monument (Rotava Basalt Organs) are remains of a Tertiary volcano and a superb example of basalt columnar erosion. The nature monument is accessible by cycle route No. 2045 from the town of Kraslice or from Favorit Hunting-Lodge. After riding for not more than a kilometre from the Rotava gamekeeper's lodge along the yellow-marked tourist path, you will reach a junction where you will take the path leading to the Rotava Basalt Organs just 1.3 km away.
The state-protected nature monument is frequently visited by tourists and it has become a symbol of Rotava. The basalt columns or organs are a part of a Tertiary volcanic belt intersecting north-western Bohemia from Bavaria up to Poland. Although dozens of examples of basalt columnar jointing may be found along the belt, especially in Doupovské hory (Doupov Mountains) and České středohoří (Bohemian Uplands), only a few are as magnificent and so finely situated in the picturesque countryside as the Rotava Basalt Organs. The mighty uncovered wall is composed of 12-metre tall cylinders aligned in the shape of fan that actually resemble organ pipes. The rock wall was uncovered during quarry activities in the past. The basalt columns were formed by the cooling of the lava. Rather rapid cooling caused intensive strain and contraction of the solidifying lava flow. As a result, the columns are aligned in the direction of the biggest temperature decline, i.e. to the area of solidification. As regards this particular surface effluent, it is vertically to the terrain surface at the time of the eruption. If we climb the top of the volcano from the left, we may walk along the basalt range to a look-out point offering a breathtaking panoramic view of the town of Rotava and the district of the town of Kraslice.
The surroundings of Rotava offer additional geologically valuable sights. These include, for example, kaolin pits or Rotavské sluňáky (Rotava Sun Stones) – i.e. one of the largest quartz blocks in the Czech Republic. In the streambed of Skřivánčí potok (Nightingale Stream) in Růžové údolí (Rose Valley), you may find granite rocks and profiles, as well as giant bowls with tangible evidence of seismic activity. The collar of a wide exploratory drift bespeaks of ore deposits.