There is an account that in the 1940s a British embassy worker, Miss Lois Jessup, went on a tour of the Hypogeum and convinced a guide to let her explore a 3ft. square "burial chamber" next to the floor of the lowest room in the last [3rd] sub-level. She claims that after squeezing through this chamber she came into a large room; where she was standing there was a large cliff with a steep drop and the floor of the cavern could not be seen. Across the cavern there was a small ledge with an opening in the wall. According the Ms. Jessup, a number of 'humanoid beings' that were covered in white hair and hunched over came out of this opening. They raised their palms in her direction and a large gust of wind filled the cavern, extinguishing the light of her candle. She then claimed that she felt something brush past her. When she went back to the Hypogeum on another occasion, she was told no such tour guide had ever worked on the site. Sometime after Miss Jessup's first visit, a group of school children and their teacher visited the Hypogeum on an outing and entered the same burial chamber, which then collapsed while they were inside. Search parties could not conduct a thorough search for the children or their teacher due to the cave-in. The parents of the children claimed that, for weeks, they could hear the voices of their children coming from under the ground in several parts of the island.

crazy night time wikipedia reading about the malta hypogeum. creepy.