Krucze Skały (Raven Rocks) next to the railway station in the village of Jerzmanice-Zdrój are the most impressive geological site in the Kaczawskie Foothils which shows Upper Cretaceous sandstones. The rock outcrops are partly natural, partly anthropogenic. The upper part of the locality is natural, with a series of crags emerging from the slope of the Kaczawa valley, shaped as angular towers, pulpits and cliff lines. Most striking is a 6 m high tower in front of the main cliff, separated from it by a narrow passage. Below the crags and adjacent to the station, the valley side was completely altered by quarrying the sandstone for building stones. The legacy of this activity are smooth vertical walls as much as 25 m high and 120 m long. Further to the north the valley side is again natural and dissected by dry valleys a few tens of metres long. These in turn are separated by natural sandstone outcrops a few metres high.
Quarrying in Jerzmanice-Zdrój was pursued at least from the 18th century, but it terminated prior to World War II and the area was developed for visitors. A rock-hewn flight of steps was made to the south of the quarry, to allow access to the upper quarry rim and a path was built along the rim. It then passes the free standing tower and descends to the valley floor among minor crags. At the foot of the sandstone cliffs a well was built in Neoclassical style, named Rock Spring.