The cave was a home long before it was a stage. Archaeologists working here have recovered Neanderthal tools and Ice Age animal bones, evidence that the Balver Höhle was used as shelter and butchery floor more than 50,000 years ago. The acoustic qualities that make it a good theater were just as useful in the Stone Age, when a fire at the back of the cave would have lit the same vault of rock the modern lighting rigs now pick out. The cultural festival itself, Festspiele Balver Höhle, formally took shape as an association in 1985, but postwar cultural use of the cave dates back to 1947, when Theodor Pröpper and Hermann Wedekind established the Balver Höhlenspiele as the region looked for places where life could resume that did not need to be built first. The cave was already there. The audience just walked in.

The artistic director from 1985 to 1996 was Hermann Wedekind, an opera director and theater man who set the cave's identity by mixing serious classical theater with international ensembles. Within a few years Balve had hosted Gryphius's tragedy Katharina von Georgien, with Werner Traud playing Shah Abbas; the VHS-Theatergruppe Iserlohn performing Arthur Miller's The Crucible; and Wedekind's own productions of Peer Gynt and The Caucasian Chalk Circle. Both Brecht and Ibsen were staged with Theaterwerkstatt Melchiorsgrund and Georgian ensembles, the choice of Georgian collaborators a recurring Balve fingerprint. Das grosse Welttheater followed in 1995 with a Georgian children's ensemble; Goethe's Iphigenie auf Tauris in 1996. Few cave theaters anywhere can claim a repertoire that includes Calderon, Brecht, Ibsen, Goethe, and Arthur Miller in one decade.

The musical reach of the festival expanded in the late 1990s when the conductor and pianist Justus Frantz began an annual residency that ran from 1995 to 2007. With his Philharmonie der Nationen, the multinational orchestra he had founded as an exercise in cultural diplomacy, Frantz conducted Tchaikovsky's Fifth Symphony in the cave to particular effect, the cavernous acoustic doing things to the closing brass that no purpose-built hall could replicate. Carmina Burana was staged in 1994 under the limestone arches. Aida followed in 2004. The Philharmonic Orchestra Hagen played under Antony Hermus in 2002. Scala and the Kolacny Brothers, the Belgian girls' choir that turned alternative rock into hushed choral arrangements, arrived in 2005.

Running alongside the high-culture programming was a children's festival that may have been the festival's most influential thread. The Balver Marchenwochen, the Balve Fairy Tale Weeks, ran from 1991 to 2008 under directors Gabriele Krieger and Josef Bertsch. A generation of Sauerland children saw their first staged play in this cave. The list of productions reads like a child's reading shelf: Robin Hood in 1995, Aladdin in 1998, Captain Nemo in 1999, Pippi in Taka-Tuka-Land in 2001, the Wizard of Oz in 2005, Peter Pan in 2008. The most successful of these adaptations was Pippi, and you can still find recordings of all of them on CD and DVD in the festival's archive. A children's theater director was appointed by the artistic director; the position passed from Werner Traud to Kai Wolters to Matthias Hay to Gabriele Krieger over the years.

Festspiele Balver Höhle is patron-supported and association-run, with Lukas Koch currently chairing the board. The federal president Johannes Rau, who died in 2006, served as patron from 1985 to 1998. The festival's signature mix has held remarkably steady across forty years. Children's fairy tales in one season slot. Classical and choral work in another. From 1970 to 2005 the cave also hosted an Internationales Jazz- und Bluesfestival, a thread that pulled jazz fans into a hall that on most nights expected Brecht. From 2002 to 2008 an Irish Folk and Celtic Music series brought in fiddle and bodhran. The cave does not care about genre. The acoustic accepts whatever you put into it and gives back something deepened by limestone. Walk in at sunset on a festival night and the difference between a cathedral and a cave starts to dissolve. The vault overhead is older than any cathedral, and the audience seated below it can feel that, whether the program says Bach, Pippi, or Tchaikovsky.