Torchwood One had a bunker beneath Soho Square, accessible by Little Compton Street. The entrance sterilised those who entered with thallo rays.
Norton Folgate took Andy Davidson and Gideon Lyme to the bunker in the 1950s, expecting to find survivors of the spores which he believed to have killed Lizbeth Hayhoe, but they instead found themselves surrounded by creatures. The trio managed to escape and Norton left the gas taps on, causing it to explode after Norton crashed the Skylon into Soho Square. (AUDIO: Parasite)