<P> Calcite, the mineral that makes up limestone, dissolves slowly in rainwater . Over time, this process can form caves . For this reason the Rock of Gibraltar contains over 100 caves . St. Michael's Cave, located halfway up the western slope of the Rock, is the most prominent and is a popular tourist attraction . </P> <P> Fossils of Neanderthals have been found at several sites in Gibraltar . In 1848, a Neanderthal woman's skull was found at Forbes' Quarry, located on the north face of the Rock . However, its significance was not recognized until after the 1856 discovery of the type specimen in the Neander Valley . Excavations in Gorham's Cave, located near sea level on the eastern side of the Rock, found evidence it was used by Neanderthals, and plant and animal remains in the cave gave evidence of Neanderthals' highly varied diet . </P> <P> The Moorish Castle is a relic of Moorish rule over Gibraltar, which lasted for 710 years . It was built in the year A.D. 711, when the Berber chieftain Tariq ibn - Ziyad first landed on the rock that still bears his name . The 17th - century Muslim historian Al - Maqqari wrote that upon landing, Tariq burned his ships . </P> <P> The principal building that remains is the Tower of Homage, a massive building of brick and very hard concrete called tapia . The upper part of the tower housed the former occupants' living apartments and Moorish bath . </P>

What is the history of the rock of gibraltar