Mountain

A mountain was a land feature which was significantly higher than its surroundings.
On Gallifrey, the Doctor grew up in the House of Lungbarrow on Mount Lung, (PROSE: Lungbarrow) while the Master's father owned land on the slopes of Mount Perdition. (TV: The End of Time)
Olympus Mons was a large volcanic mountain on Mars. According to Tanya Webster, it was "the biggest volcano in known creation" and was located "just across the plain" from Izdaal's tomb. (AUDIO: Red Dawn) Rudy Zoom claimed he was the first man to climb it. (COMIC: The Eye of Torment) The central control facility for the Sol Transit System was located inside Olympus Mons, as well as the power grid established by Fusion Corp. (PROSE: Transit)
The Earth mountain Mount Everest was first successfully climbed by humans in 1953. (TV: The Idiot's Lantern) Santiago Jones visited it during one of his journeys. (TV: Death of the Doctor)
"The company" blasted mountains to find minerals on Kromon. (AUDIO: The Creed of the Kromon)
The mountains on Judoonia were 1,000 miles high. (AUDIO: Judoon in Chains)
On Ashtallah, the Valley of the Ashtallans bordered a large mountain range. When Barbara Wright and Susan Foreman first met the Ashtallans, Barbara claimed that they came from beyond the mountains, which Susan noted was not technically a lie. (AUDIO: The Invention of Death)
The Dalek City was built near a large mountain range, giving the city a natural defence. (TV: The Daleks)
The mountains surrounding the Sensorite city on Sense Sphere were yellow, and contained natural springs. (TV: "Hidden Danger")
Mount Olympus on Earth was said to be the home of the Olympians. By one account, the mountain was the site of a portal to Olympus, described as "not exactly a parallel universe, but an alternative world of transdimensional locations" by Hermes. (PROSE: Deadly Reunion)