Azores

The Azores, also known as the Western Isles (TV: War of the Sontarans) were a group of Portuguese islands. (PROSE: The Fortunate Isles) They were located in the Atlantic Ocean, (TV: The Underwater Menace) around 600 miles west of Portugal. The Azores included the islands of Santa Maria (TV: The Chase) and São Miguel. (PROSE: The Fortunate Isles)

History
After Ash stowed away aboard the El Galgo in Seville in 1485, the ship followed the River Guadalquivir to the sea, then headed west towards the Azores. (PROSE: The Fortunate Isles)

On 25 November 1872, the Mary Celeste sighted the island of Santa Maria, which was one of the Azores. (TV: The Chase) On 4 December, the Mary Celeste was found, abandoned, midway between the Azores and Portugal. (PROSE: The Chase)

Professor Zaroff told the Second Doctor that their location was west of Gibraltar, south of the Azores, on the Atlantic Ridge. From this information, the Doctor deduced that they were in Atlantis. (TV: The Underwater Menace)