A vertical or steeply-sided natural opening a few tens to a few hundred meters deep, formed by solution or erosion of vertical or sub-vertical fractures or fissures by down flowing surface water. Such a pit, formed from above, may connect with a chimney formed from below. Synonyms: (French.) karst shaft; (German.) Schacht, Schaft; (Greek.) karstikos lakkos; (Italian.) voragine, inghiottitoio; (Russian.) karstovaja shahta; (Spanish.) sima; (Turkish.) karst bacasi; (Yugoslavian.) jama. Related to dolina, jama, obruk, pit.