This is a unique underground prehistoric temple in the city of Paola, Malta, a UNESCO World Heritage Site, built around 6000 years ago, a site of global importance, even older than the pyramids. This unique monument was inscribed on the UNESCO World Heritage List in 1981, as a site that bears unique testimony to a civilization that has disappeared (criterion iii).

The site yielded a wealth of archaeological material, including pottery, human bones, personal ornaments, little carved animals and larger figurines. The Hypogeum at Ħal Saflieni is a unique monument, consisting of halls, chambers and passages hewn out of globigerina limestone. The complex is dug in three levels: the upper level, the middle level, and the lower level, with the site users digging deeper as space became limited.

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. Some of the smoothly-finished chambers of the middle level recall the interiors of above-ground megalithic structures. The deepest room in the lower level has four side niches and lies 10.6 metres under road level.