Cheltenham

Cheltenham was a location in England. The GCHQ building was located there. (AUDIO: Iceberg, TV: Revolution of the Daleks)

History
On 1 January 2019, a Reconnaisance Dalek penetrated the GCHQ and commandeered its resources in an attempt to contact the Dalek invasion fleet, but was stopped by the Thirteenth Doctor and Team TARDIS. (TV: Resolution) In the aftermath of the Recon Scout Incident, the Dalek's melted casing was removed from the scene. (TV: Revolution of the Daleks)

Other references
The Tenth Doctor claimed to be from Cheltenham. (COMIC: The First)