Vatican City
From Tardis Wiki, the free Doctor Who reference
Vatican City, or simply the Vatican, was the capital of the Catholic Church. In 2009, the "Holy See of Vatican City" was among the nations which agreed to let John Frobisher speak on their behalf to the 456. (TV: Children of Earth: Day Three)
In a virtual reality world created by the Monks, the Twelfth Doctor visited the Vatican to read the Veritas. (TV: Extremis)
In an alternate timeline caused by the time field, the Pandorica, which was guarded by the Lone Centurion, was donated to the Vatican in 1231. (TV: The Big Bang)
There was a floating Vatican City in Europa in the 33rd century. (PROSE: Managra)