The cave was first mentioned in 1647 by the Maltese historian Giovanni Francesco Abela (1582–1655). Għar Dalam became known as a fossil bone site in 1865, when the Genoese geologist Arturo Issel (1842–1922), searching for Neanderthal remains, discovered the first hippopotamus bones there. In 1892, the English teacher John Henry Cooke conducted several excavations, uncovering a large number of Pleistocene animal bones. The success of these investigations led to the cave being visited by numerous fossil collectors over the next 30 years. It wasn't until 1922 that new, larger-scale scientific investigations were conducted. These were initiated by Gertrude Caton-Thompson (1888–1985), a British archaeologist, and later continued by her Maltese colleague Joseph G. Baldacchino (1894–1974). The vast amount of finds soon led to a storage problem, which is why a house was built over the cave by 1930. The cave itself was opened to visitors in March 1933, while excavations ended in 1937. Just a year earlier, a museum had been established on site.[1][2]
During World War II, during the Second Great Siege of Malta, the cave served as a refuge for the population from bombing raids. The British armed forces also used it to store aircraft fuel from October 1940. The cave and museum did not reopen until 1947. However, no major excavations were carried out after the end of the Second World War. A few smaller excavations were carried out by the German paleontologist Gerhard Storch in the 1970s, which affected all sedimentary layers. Today, the cave is largely empty, with only two sedimentary columns remaining as reference profiles for clarifying the stratigraphy. A new, significantly larger exhibition hall opened next to the old museum building in 2002.
Source: Wikipedia