Before revision: The Ħal-Saflieni Hypogeum in Paola, Malta, is the oldest example of a prehistoric hypogeum, the earliest phase dating to 3600–3300 BC; it is a complex of underground chambers, halls and passages covering approximately on three levels, partly carved to imitate temple architecture and containing extensive prehistoric art.
After revision: The Ħal Saflieni Hypogeum in Paola, Malta, is the oldest example of a prehistoric hypogeum, the earliest phase dating to 3600–3300 BC; it is a complex of underground chambers, halls and passages covering approximately on three levels, partly carved to imitate temple architecture and containing extensive prehistoric art.