This is the part of the reservoir that is accessible to speleologists. Other early speleologists include Herbert E. Balch. Those caves are also well coveted by known speleologists who have explored their passageways. Furthermore, he is the patron saint of speleologists. Kiernan and a group of cavers (speleologists) found over 100 caves in the region. In 1969, the Speleotherapy Commission was founded at International Union of Speleologists. The Federation represents the Bulgarian cavers and speleologists. Slavyanka has a pronounced karst character and thus features over 30 caves, attracting many speleologists. Access by organized groups and experienced speleologists is allowed with a permit. The underground aspect is often of particular interest, and extends beyond railbuffs to urban speleologists. It was found in 1963 by the Speleologists Club and excavated by Father Hours. They are of importance to speleologists because they have formed in sandstone. Among speleologists, "ice cave" is the proper English term.