Canary Wharf
From Tardis Wiki, the free Doctor Who reference
Canary Wharf tower or "Torchwood Tower" which it was known as to its personnel was located in centeral London and home to Torchwood 1.
In was used at the tower of One Canada Square to reach the height of the "Radar Black Spot" which opened the void. After the Battle of Canary Wharf, the tower was presumed shut down after Torchwood one was destroyed.