The Čertova stěna – Luč NNR lies in the south of the Jihočeský kraj – South Bohemian Region and was founded in 1992 by merging two previously existing reserves. Mt. Luč had been a protected territory since 1934 and the Čertova stěna cliff since 1956. In 2004 the NNR territory was extended to its current area of 132.6 ha. The NNR includes a complex of communities of open talus, relict pine forests with spruce and birch, fragments of herb-rich beechwoods, talus and ravine forests and acidophilous fir slope stands in the rugged terrain of the deeply incised Vltava river valley. Other reasons for protecting the area are the rich insect and bird life found here.
The geological basement is generally formed by muscovite-biotite paragneiss of the Moldanubicum Zone. The whole territory is extremely rugged and we can find rock formations which demonstrate the effects of periglacial relief shaping frost-riven cliffs, tors, castle koppies and extensive boulder fields. The most well-known formation, Čertova stěna (Devil’s Cliff) is a massive granite rock wall under which lies an extensive boulder field formed of piles of massive blocks up to 2 x 3 m in size. A block field of large boulders is also located on the SE slopes of Mt. Luč. Part of the natural river channel of the riverbed is filled with granite boulders which display typical evorsion forms, the so-called potholes.
A notable complex of relict forest and non-forest vegetation communities on rocky localities has been preserved on the NNR territory. The vegetation on the rock formations and exposed talus consists mainly of moss and lichen communities including the rare species of cup lichen Cladonia stellaris and the tube lichen Parmelia centrifuga, which has its only current locality in the Czech Republic on Mt. Luč.
The most notable vegetation community are the relict acidophilous pine growths with birch and spruce, with predominant tree species Scots pine (Pinus sylvestris) and Carpathian birch (Betula carpatica), accompanied by silver birch (Betula pendula), Norway spruce (Picea abies), rowan (Sorbus aucuparia) and occasionally sessile oak (Quercus petraea). The herb layer is very poor in species but includes bilberry (Vaccinium myrtillus), cowberry (Vaccinium vitis-idaea) and wavy hair-grass (Avenella flexuosa). In more compact pine stands away from the rocky talus we can also find the species of phytogeographical significance – the heath Erica carnea. The narrow alluvial belt of the Vltava river is formed by linear growths of black alder (Alnus glutinosa) with smaller populations of grey alder (Alnus incana) and crack willow (Salix fragilis) on both banks of the river.
Very valuable invertebrate communities, especially of insects and spiders, including the protected bee beetle (Trichius fasciatus), inhabit the forested and forest-free talus slopes. The bird community here is also rich and includes the chaffinch (Fringilla coelebs), robin (Erithacus rubecula), coal tit (Parus ater) and chiff-chaff (Phylloscopus collybita). In the relict pinewoods on the boulder fields a typical species is the redstart (Phoenicurus phoenicurus). The NNR is a traditional nesting territory of the eagle owl (Bubo bubo).
The NNR territory is very attractive for tourists and the rocky summit of the Čertova stěna cliffs is accessible from the car park by the Vyšší Brod – Loučovice road and a marked hiking and cycle trail run along the other side of the river. Information panels for visitors are placed above and below the Devil’s Cliff.