British Telecom Tower

At some point, the Sixth Doctor and Peri Brown landed the TARDIS outside the British Telecom Tower. The company "modernised" the vehicle, making it no longer dimensionally transcendental. After the fact, Peri claimed she had warned the Doctor of this eventuality. (NOTVALID: Doctor Who? 119)

Behind the scenes
Telecom Tower is an alternate name for the Post Office Tower, prominently featured in The War Machines. The connection has not been made in-universe as of yet, however.