No.24 Marigold Lane was a house located in Stamford Bridge, on Marigold Lane. In the 1970s, it was actually the Time Lords' Research and Development Repository, disguised as a suburban household using synchronous dimensional architecture. Rather than simply having an outer shell, the house and the weapons repository both existed, dimensionally on top of one another. A broom cupboard door led into a seemingly endless space, where the Time Lords kept their weapons.
Tandeeka, a Time Lord agent disguised as the widowed "Mrs Wilson", was keeping the Heavenly Paradigm under lock and key there, and after finding this Time Lord, the War Master had Cole Jarnish killed to power the Paradigm, his usefulness having come to an end. (AUDIO: The Heavenly Paradigm)