The Hypogeum, or underground cavity, is a unique monument and superb example of architecture in the negative. Excavation has yielded a wealth of archaeological material including pottery, human bones, personal ornaments such as beads and amulets, little carved animals and larger figurines.
The Hypogeum consists of halls, chambers and passages hewn out of the living rock and covering some 500 square metres. The rock-cut chambers are of diverse shapes and sizes, finished to different standards of workmanship. The complex is grouped in three levels – the upper level (3600-3300 BC), the middle level (3300-3000 BC) and the lower level (3150 -2500 BC). The deepest room in the lower level is 10.6 metres under road surface.
The upper level consists of a large hollow with a central passage and burial chambers cut on each side. The middle level consists of various chambers very smoothly finished, which give the impression of built masonry.