The Na Skále NNM lies about 1km south-east of the village of Hněvotín u Olomouce, in the parishes of Hněvotín and Žerůvky, in the Olomoucký kraj-Olomouc Region. The monument was declared in 1977 and covers an area of 4.56ha at elevations of 242-263 metres above sea level. The protected area consists of a rugged terrain depression on the site of a former limestone quarry with fragments of previously extensive sub-xerothermal grass-herb and shrub communities.
The territory is a part of the Hněvotín – Olomouc fault block, which is built of small outcrops of pre-Devonian crystalline rocks of the Brunovistulicum, respectively the Olomouc Massif and its contact zone, which is overlain with transgressively laid Devonian sediments. These are built of basal quartzite, over which there are strata of dolomitic limestone and predominantly fine-grained, grey limestone from the upper Devonian. The Palaeozoic development here is concluded by greywackes from the Drahanský Culm. The majority of the crystalline anticlinal dome later subsided as a consequence of tectonic movements and was covered by Tertiary and Quaternary deposits of the Hornomoravský úval Depression.
On the territory we can find shrub communities of the Prunion spinosae alliance, as well as grass-herb communities of the Bromion erecti alliance and Sedo-Scleranthetea class. Of the 260 vascular plant species which have been recorded here the most notable type is the subspecies of large thyme (Thymus pulegioides ssp. carniolicus), which has its only locality in the Czech Republic at Na Skále. Of the many other notable plants growing here we can mention the yarrow Achillea pannonica, the aster Aster amellus, dwarf sedge (Carex humilis), dwarf cherry (Cerasus fruticosa), the widow flower Knautia kitaibelii, knapweed broomrape (Orobanche elatior), the umbellifer Peucedanum alsatium, broad-leaved spignel (Peucedanum cervaria), cut-leaf self-heal (Prunella grandiflora), spiked speedwell (Pseudolysimachion spicatum), Celtic rose (Rosa gallica), the scabious Scabiosa canescens, lesser meadow-rue (Thalictium minus) and purple mullein (Verbascum phoenicum).
The isolation of this steppe territory may be the reason why the butterfly fauna in the reserve is relatively poor. Only 55 species have been recorded here and the majority of them have a wide ecological valence. An exception is the specific steppe butterfly – the chalk hill blue (Polyommatus coridon). As many as 34 species of ants were recorded here in the past although in recent years only 20 species have been confirmed, but this includes several protected species such as Formica cunicularia, Formica fusca and Formica rufibarbis. The grasshopper Phaneroptera falcata can also be found here, as can the sand lizard (Lacerta agilis). Birds which nest on the territory of the monument include the partridge (Perdix perdix), red-backed shrike (Lanius collurio), nightingale (Luscinia megarhynchos), woodpigeon (Columba palumbus), turtle dove (Streptopelia turtur), goldfinch (Carduelis carduelis), siskin (Carduelis spinus), linnet (Carduelis cannabina), cuckoo (Cuculus canorus), kestrel (Falco tinnunculus), magpie (Pica pica), little owl (Athene noctua), great spotted woodpecker (Dendrocopos major), wren (Troglodytes