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Mt. Rataj (350 m) in the eastern part of the Kaczawskie Foothills may look inconspicuous from a distance, but it is home to one of the most impressive geological outcrops in the region. The east-facing slopes are undercut by a large abandoned quarry. The quarry wall reveals a fan-shaped pattern of joints, known as columnar jointing. It originated during cooling of lava in the former volcanic conduit and resultant shrinking. The fan spreads out to the bottom. In the central part of the quarry, within the 20 m high precipice under the peak, one can see 20–30 cm thick columns standing upright. In the outer parts of the same precipice the columns are inclined inward. In the southern quarry wall in turn, we see the columns in cross-section, meaning they are lying flat. It should be noted that joints form perpendicular to the cooling surface which was the wall of the volcanic conduit. Thus, the preserved full pattern of an inverted fan shows that the conduit was rather small and volcanic activity involved just one phase.
In the summit part of Mt. Rataj a large hilltop fort was built in the middle medieval times. Its remains include two lines of ramparts and separating moats. In the late medieval times (13–15th century) a small castle, or watchtower, stood on the top of the hill, but no traces of its existence are left except a small section of a wall built of local basaltic stone.