In the middle of the Skevonys Outcrop a deep and wide cleft has been eroded. Lower down some parts are damper due to underground waters. This site since 1984 has been a national natural monument. This is listed as one of the most valuable geological sites in North Western Europe. The crest of the Skevonys Outcrop appears like a gigantic crocodile. This huge feature of nature was created of many thousands of years by the action of the Nemunas river, long before the loops were created. The result is a deeply slope site with richly evident soil strata. The unique Skevonys rock formations and the surrounding area including the distinct Birstonas erosion spur are preserved as a geomorphologic reserve.