Through this process, tiny cracks in The Rock's geological fault grew into long passages and large caverns over thousands of years.

The numerous stalactites and stalagmites in the cave are formed by an accumulation of traces of dissolved rock deposited by water dripping from the ground above.

The first official archaeological excavation of the cave was carried out by the Governor of the military prison, Captain Frederick Brome, commencing in April 1863 and continuing until December 1867.

[7] He discovered numerous prehistoric artifacts such as stone axes and arrow heads, shell jewelry, and bone needles as well as a large collection of pottery.

It is believed that St. Michael's Cave has had a military use since the Berber general Tariq ibn Ziyad led the Umayyad conquest of Hispania in 711 AD.

Just after Gibraltar's capture by Anglo-Dutch forces in 1704, 500 Spanish troops concealed themselves within the cave overnight after having ascended through a path led by goatherd Simón Susarte, before an unsuccessful attempt to surprise the garrison.

The series of descending chambers are riddled with examples of almost all known cave formations, including an underground lake of crystal clear water.

It has been a regular venue for events such as dramas and son et lumière shows as well as the annual Miss Gibraltar beauty pageant.

[13] Presently the cave is one of Gibraltar's top tourist attractions and is open daily to the public receiving almost 1,000,000 visitors a year.

The cave is in a completely natural state, although fully lit and kitted out with ropes to aid minor climbing and scrambling.