St Michael’s Cave was long believed to be bottomless. This probably gave birth to the story that the Rock of Gibraltar was linked to the Africa by a subterranean passage under the Strait of Gibraltar. The famous macaques were said to have come to Gibraltar through this subterranean passage. Pomponious Mela, one of the earliest geographers who lived about the beginning of the Christian era, spoke about the cave in his writings.
It was at one time believed that in 1704 Spanish troops spent a night in the cave after climbing the precipitous east face of the Rock. Another story about the cave recounts how a Colonel Mitchell and another officer were said to have descended into the cave at some unspecified date before 1840 and were never seen again. During WWII the cave was prepared as an emergency hospital, but was never used as such. The cave is open to visitors and makes a unique auditorium for concerts, ballet and drama.
It has been in use as a theatre since the early sixties with capacity for 600 persons. At some period during the history of this cave, part of a stalagmite became too heavy on one side and fell, possibly thousands of years ago. It now lies on its side at the far end of the main chamber, cemented through the years by nature to the floor of the cave. In 1972 a slice was cut off from the top end which revealed the interior structure of the stalagmite in a most dramatic fashion.