The Hypogeum is an enormous subterranean structure excavated c. 2500 B.C., using cyclopean rigging to lift huge blocks of coralline limestone. Perhaps originally a sanctuary, it became a necropolis in prehistoric times.
Hal Saflieni Hypogeum is a cultural property of exceptional prehistoric value. This unique monument dates back to early antiquity (about 2500 BC) and it is the only known example of a subterranean structure of the Bronze Age.
The hypogeum was discovered accidentally in 1902 by a stonemason who was laying the foundations of some houses on the island of Malta. Temi Zammit, the first Director of Malta's Museums Department, assumed responsibility for the excavation. His excavation yielded a wealth of archaeological material including much pottery and human bones, personal ornaments such as beads and amulets, little carved animals and larger figurines.
This 'labyrinth', as it is often called, consists of a series of elliptical chambers and alveoli of varying importance, to which access is gained by different corridors. The megalithic walls are constructed of cyclopean masonry - large irregular blocks of chalky coralline stone without mortar - which was summarily dressed with rudimentary tools of flint and obsidian. The principal rooms distinguish themselves by their domed vaulting and by the elaborate structure of false bays inspired by the doorways and windows of contemporary terrestrial constructions. The hypogeum, which was originally conceived as a sanctuary, perhaps an oracle, from the prehistoric period was transformed into an ossuary, as borne out by the remains of more than 7,000 individuals discovered during the course of the excavation.
The upper level consists of a large hollow with a central passage and burial chambers cut on each side. One of the chambers still contains original burial deposits. The middle level consists of various chambers very smoothly finished, which give the impression of built masonry. The workmanship is all the more impressive when it is considered that the chambers were meticulously carved using only flint and stone tools. Curvilinear and spiral paintings in red ochre are still visible in some areas. One of the niches in the 'Oracle Chamber' has the characteristic of echoing deep sounds. The carved facade is magnificent and the quality of its architecture is in a remarkable state of preservation.