Hagia Sofia

The  was a religious temple in 10th century Constantinople. The Fifth Doctor was supposed to take Peri Brown to see it, though she couldn't remember its full name and called it "Hagia-something". (PROSE: Methuselah)

Hagia Sofia, (TV: The Poison Sky) along with the rest of Istanbul, was shrouded in toxic fumes as a result of the 2009 Sontaran invasion of Earth. Kirsty Wark reported on this for BBC News 24. (PROSE: The Time Travellers' Almanac)