The Hal Saflieni Hypogeum is an ancient underground burial site located in Paola, Malta. Dating back to approximately 4000 BC, it is among the world's oldest and best-preserved subterranean structures. The Hypogeum was used both as a sanctuary and a necropolis, with archaeologists estimating that it once contained the remains of over 7,000 individuals.
Discovered accidentally in 1902 during construction work, the Hypogeum offers a unique glimpse into Malta's Neolithic period. Its intricate system of chambers, halls, and passages was meticulously carved into the limestone using rudimentary tools. The site's architecture mirrors that of contemporary megalithic temples found above ground, showcasing the advanced craftsmanship of its builders.