1171: Probably the oldest mention of mining activities on Hochobir (charter)
1696: The first documented evidence of mining on Hochobir
1870: Discovery of the Obir dripstone caves while advancing into the Mark tunnel
1989 Establishment of the company Obir-Tropfsteinhöhlen Errichtungs- und Betriebsges. m. b. H. by the project manager Walter Jerlich.
1991: Official opening of the Obir dripstone caves for tours; the start of guided tours (July 5)
1999 The half-millionth visitor
2003: The making of operational mine plan, through which all processes in caves were governed 2004: The first installation of lighting, sound and visual effects in caves (base-projection HDTV )
2007: Installation of the first HDTV -projection in a cave in the world
