What if the rocks beneath our feet could whisper tales from nearly 400 million years ago? That is the story of n\u00e1rodn\u00ed p\u0159\u00edrodn\u00ed pam\u00e1tka U Nov\u00e9ho ml\u00fdna. This national natural monument spans 12.6962 hectares. It lies on the right bank of the Dalejsk\u00fd potok. This is above the railway line from Prague to Rudn\u00e1. The monument is near the Holyn\u011b stop.
U Nov\u00e9ho ml\u00fdna includes the former Prastav quarry. It also includes its immediate surroundings. These areas fall within the cadastral territories of Hlubo\u010depy and Holyn\u011b. These are part of Prague. The elevation ranges from 255 to 310 meters. The Agency for Nature Conservation and Landscape Protection of the Czech Republic manages this protected area. Its regional office is in Central Bohemia.
Geologically, U Nov\u00e9ho ml\u00fdna features profiles from the Lower and Middle Devonian periods. It is a site rich in fossils. One can find communities of warm-loving grassy and rocky steppes. Numerous fossils exist here. These include brachiopods, clams, trilobites and tentaculites. The rocks are limestone. Specifically, they are gray fine-grained limestones. These date back to the Devonian Prague Formation. Streaks of solid, thinly layered, gray-green Daleje shales are also visible.
The abandoned Prastav quarry within U Nov\u00e9ho ml\u00fdna protects an international parastratotype. This serves as an auxiliary standard for the set of layers. These layers mark the boundary between the Lower and Middle Devonian. This boundary is roughly 397.5 million years old. It is defined by the first appearance of the conodont Polygnathus costatus partitus.
The flora and fauna at U Nov\u00e9ho ml\u00fdna mirror those of the Prokopsk\u00e9 \u00fadol\u00ed. Much of the area has been artificially reforested with black pine and acacia. Former fields now host plantings of linden, oak and Scots pine. Gray partridges nest near the edges of the rocky steppe. The area is undergoing secondary succession.
At first glance, the site might seem unattractive. This is due to overgrown vegetation and many ruderal species. Examples are wood avens and small-flowered touch-me-not. Cleavers are also common. Most of the area is covered by planted forest. This is mainly deciduous with shrubs. Pine trees dominate along the railway line. The undergrowth of the deciduous forest is sparse. However, white helleborine is abundant. This is especially so in stands of small-leaved lime and hornbeam. This is a common phenomenon in Prague in recent years.
On a rocky outcrop above the railway line in the northern part of the area, there are several interesting species. These include large-flowered rock-rose and moon carrot. Germander and feather grass are present. Common houseleek and hairy inula grow here. Chiltern cornflower and Bohemian pasqueflower can be found. The pine forest is home to blue moor grass. Branched St Bernard’s-lily also grows there. Several plants of erect clematis are present too.
Other interesting species grow on the rocky edge of the Prastav quarry. These include yellow scabious and hoary rock-rose. Sainfoin and common Biscutella can be seen. The beloved clustered pink also thrives here.
Moving towards Prague, we find warm grasslands. These contain many common and rarer species. Common examples include sickle medick and meadow sage. Whorled clary is also present. Greater knapweed and clustered bellflower add colour. Hairy milk-vetch and erect brome contribute to the diversity. Rarer finds include burnt-tip bugloss and flax-leaved daphne. Dwarf thistle and large-flowered selfheal are present. Most notably, one can spot the woodland anemone. Other rare plants reported in the area include St Bernard’s lily and Cornelian cherry. Czech Gagea and Fine-leaved feather grass are also found. The national natural monument U Nov\u00e9ho ml\u00fdna is a window into a world long past. Its blend of geological significance and ecological diversity creates a unique environment. It is a place where the distant past is always present.