The Radouč NNM was declared in 1977 to protect rare calciphilous and thermophilous communities of the opoka rocks with the unique occurrence of the rock-rose Fumana procumbens in Bohemia. The rock-rose was first recorded here in the late 19th century. The locality has been protected since 1922 and a reserve was declared in 1933, but this only protected an area of 30m². The protected area lies in the Středočeský kraj – Central Bohemian Region, on the edge of the town of Mladá Boleslav and in the parish of Debř. The national nature monument covers a part of the rocky slopes on the left-bank of the Jizera river valley at elevations of 225-240 metres above sea level.
The geological basement is built of limey sandstones of Cretaceous age, which emerge in the form of natural rocky outcrops, but are also exposed in the central part of the monument where we can find an old quarry by the bridge to Podlázky. Shallow soils, Pararendzinas and Lithosols in their initial phases have developed on the calcareous sandstones on the edge of the rocks. A sand and gravel plateau neighbours the monument and this is also of great value for nature protection. This plateau is covered with grasslands with grey hair-grass (Coryneporus canescens) and also plays host to a colony of European souslik (Spermophillus citellus). Part of this plateau lies within the buffer zone of the national nature monument. This area was also used as a military training area in the past and this usage has helped to maintain the pioneer vegetation on sand here.
The current forest-free vegetation at Radouč is the result of grazing in the past and other human activities. The false acacias which had been planted in the lower part of the territory and their regenerating shoots were liquidated by grazing goats, which has maintained the forest-free conditions here. A mosaic of shrub growths can presently be found in the monument and include dogwood, privet, hawthorn and wild roses, rock vegetation on the rocky terraces, as well as a variety of steppe communities, which occur on small areas around the small rocky outcrops and around the quarry, according to the depth of the soil. The majority of the areas with deeper soils are covered with thermophilous grasslands with drooping tor-grass (Brachypodium pinnatum) or erect brome (Bromus erectus). Fescue grasslands with the fescues Festuca pallens and Festuca valesiaca are another type of vegetation which can be found on the territory of Radouč NNM. The dominant grasses are complemented by other species such as beard-grass (Bothriocola ischaemum), the feather-grass Stipa joannis, the hair-grasses Koeleria pyramidata and Koeleria macrantha, the melic grass Melica transsilvanica and sedges such as the dwarf sedge (Carex humilis) or the sedge Carex tomentosa. The false oat-grass (Arrhenatherion elatius) and cocksfoot (Dactylis glomerata) are expanding into areas which are more nutrient-rich.
On the rocky slopes and small terraces we can find dry grassland species with a wide amplitude such as the sandy cinquefoil Potentilla arenaria, the Carthusian pink (Dianthus carthusianorum subsp. carthusianorum), the garlic Allium senescens subsp. montanum, in addition to succulent species such as the biting stonecrop (Sedum acre) and the stonecrop Sedum bononiense. Spleenworts (Asplenium sp.) grow in crevices in the rocks. A rare flower that can be seen at Radouč in the springtime is the Bohemian small pasque flower (Pulsatilla pratensis subs. bohemica), whereas the slops are covered with light-coloured flowers of the St. Bernard’s lily (Anthericum ramosum) and yellow scabious (Scabiosa ochroleuca) in the summertime, whereas the slope is covered with the yellow flowers of the goldilocks aster (Aster linosyris) in the autumn. The most significant plant which grows at Radouč NNM is the rock-rose Fumana procumbens, which only has a small population of several dozen individuals at the monument. Radouč is the only locality for this rock-rose in Bohemia, which can also be found in the Czech Republic in South Moravia, where the northern border of its contiguous distribution lies. The rock-rose only blooms for a very short period with the flowers opening in the morning and the petals falling off the same day in the afternoon. This rare plant only grows on part of the locality – on the upper section of the rocky slopes, where it is endangered by the numbers of people who move around on the rocky outcrops.
In addition to thermophilous plant species the locality also plays host to a number of animals which are typical for steppe localities. These include the ladybird spider Eresus cinnaberinus¸ the comb-footed spider Dipoena melanogaster and the ground spider Zelotes longipes. The tiny thermophilous gastropod Pupilla triplicata is a notable species which has been recorded here Beetles such as the oil beetle Meloe violaceus and the European rhinoceros beetle (Oryctes nasicornis) live here. The rhinoceros beetles are bound to the neighbouring oakwoods in the buffer zone of the national nature monument.
The main management activities on the territory are liquidation of invasive species and maintaining the forest-free conditions. The most suitable method is animal grazing but this is difficult to achieve due to the proximity to the town and the heavy traffic on the roads which run next to the monument. The territory is endangered by excessive visitor numbers and increasing nutrient levels, but also the spread of wood small-reed (Calamagrostis epigeios).