the most striking landforms are the various limestone formations: outcrops, caves, grottoes, and underground rivers. the rocky banks of the nugush and belaya rives reach 150 meters in height. the "kuperlya natural bridge" is a karst formation that is 20 meters above the ground and 10 meters across; it is the remains of a former underground river. there are 30 known caves in the park, with 8.2 km of major passageways. one cave, the sumgan cave, is the largest cave in the urals, with major and minor passages up to 10 km long, and reaching down to a depth of 126 meters. the sumgan cave is located in a particular isolated terrain known as "kutuk-sumgan" ("kutuk" - "water well", "sumgan" - "dived").