The Gellért Hill Cave is part of a network of caves within Gellért Hill in Budapest, Hungary. The cave is also referred to as "Saint Ivan's Cave", regarding a hermit who lived there and is believed to have used the natural thermal water of a muddy lake next to the cave to heal the sick. It is likely that this same water fed the pools of the old Sáros fürdő ("Muddy Baths"), now called Gellért Baths.
As the Iron Curtain disintegrated, the Chapel reopened on 27 August 1989 with the destruction of the thick concrete wall that had sealed the cave. By 1992, the Chapel had been restored and the Pauline Order had returned to the cave. Today, the monks continue to perform religious functions within, though the cave is also a common tourist attraction.