Tunguska province
The Tunguska province was a region of Russia.
In 1908, the region experienced a mysterious explosion that denuded a forest in and around the Tunguska Basin. The explosion was never completely explained. One account revealed that a 21st century human named El Ape accidentally set off a nuclear explosion in the valley while travelling with the Seventh Doctor in search of the Monk. (DWM: Follow That TARDIS!) Another suggested that the explosion might have been caused by a Prastaki trading vessel crashing there. (WEB: www.bbc.co.uk/sja/sites/alienobjects/)
In any event, the Tunguska Scroll was discovered in this Earth region. (SJA: Enemy of the Bane)
At some point in the early 20th century, a Sontaran scout ship was believed to have crashed in Tunguska. The wreckage was obtained by UNIT and kept in the Vault. (CC: Tales from the Vault)