The northern part of the Kaczawskie Foothills is largely composed of Cretaceous sandstones dating back approximately 90 million years. They are similar in terms of age and origin to those found in the Table Mountains, but one would search in vain for similarly spectacular rock formations as those renowned in the Table Mountains. Nevertheless, a few locations featuring sandstone rocks deserve closer attention, and one such place is the lower section of the Drążnica Valley near Złotoryja, where several rock formations of interest can be found. A convenient starting point is the car park along the road from Złotoryja towards Świerzawa, where the green hiking trail leads to sandstone cliffs several metres high within a few minutes. Soon, you will reach the first of these peculiar features – Wilcza Jama (Wolf’s Den).
Wilcza Jama
Wilcza Jama is a rock shelter with a length of 7 metres and a flat floor. What led to its formation? The answer to this question can be obtained by examining the rock wall. It is mainly formed by sandstones. In the upper part, lamination is clearly visible – individual beds have thicknesses ranging from 15 to 30 cm and continue along the entire length of the wall. Below the cave entrance, we also observe massive sandstone. Meanwhile, at the height corresponding to the cave floor and the rock ledge in front of its entrance, there is a layer of a slightly different type, approximately 40 cm thick. Individual quartz grains in this layer are generally larger than 2 mm in diameter, indicating that we are dealing with a conglomerate. Let’s also note that the rock appears to be full of “holes” – it is highly porous, indicating that water can easily circulate through the interior of the rock mass. Standing at a certain distance from the rock wall, it is also easy to notice that the sandstone beds are intersected by vertical fractures, and the entrance opening of Wilcza Jama is precisely located on one of them.
Therefore, the cave developed at the intersection of two structures: the bed of porous conglomerate and a vertical fracture. Both of these structures, although for slightly different reasons, are zones of increased underground water flow. Rainwater soaks into the ground, then seeks the fastest drainage paths, flowing towards the slope of the valley where it resurfaces. Flowing within the porous and loosely cemented conglomerate, it washes away and dissolves the cement, and then removes the quartz and feldspar grains, which are the main constituents of the rock. In this way, a horizontal depression was formed and expanded, over which a rock overhang hung. Similarly, the waters flowing along the vertical fracture had a destructive effect on the sandstone. Hence, the niche in the rock wall developed not only in depth but gradually upward as well. The discussed process of leaching mineral material from the rock is called suffosion and is typical for loosely cemented, porous substrates. It is common in loess, as can be observed, among other places, in loess gullies on the slopes of the Kaczawa Valley in Złotoryja.
Niedźwiedzia Jama and Skalny Wodospad
Continuing further, after a few minutes, we will reach a spacious, horizontally developed rock niche with a width of 12 metres, referred to as Niedźwiedzia Jama (Bear’s Den). Its origin is similar to the genesis of Wilcza Jama and is also related to the presence of a bed of porous conglomerate. However, in this location, there is no distinct vertical fracturing, so the cave did not enlarge upward. The third formation is located several dozen metres up the valley and is known as Skalny Wodospad (Rock Waterfall). It is a two-tiered rock ledge with a height of about 7 metres, above which is the outlet of a dry valley. For the majority of the year, the Rock Waterfall remains dry, but occasionally water flows through it, carving and enlarging the basin below as it cascades from the upper ledge. However, the most captivating sight is the Rock Waterfall in winter when the water flowing from the rock fractures freezes, forming a spectacular, multi-tiered icefall. It’s worth “hunting” for this view – it will stay in your memory for a long time.
