Mount Snowdon

Mount Snowdon was the tallest mountain in Wales, at a height of around 1,085 metres (3,560 feet). A team from Torchwood 1 dug up the remains of an alien spacecraft buried at the foot of the craft and found Magna-Clamps buried there. (DW: Army of Ghosts)

The Immortality Gate was also discovered in a ship here, also recovered by Torchwood. (DW: The End of Time)

UNIT Base 5 was built into Mount Snowdon. (SJA: Death of the Doctor)