From Discworld & Terry Pratchett Wiki
The central mountain range of the disc. The highest peak is, of course, Cori Celesti, the home of the Gods, of which there are several. The Ramtop Mountains stretch 'from the frozen lands near the Hub all the way, via a lengthy archipelago, to the warm seas which flow endlessly into space over the rim'.
Because of their proximity to the most dense part of the disc's magical field, the Ramtops is home to several weird and wonderful creatures, and some weird and wonderful people. More than this, the mountains themselves serve as conductors for a lot of the Disc's raw magic to earth itself. It crackles invisibly from peak to peak, causing leaves on trees to move even when there's no breeze. Around the Ramtops, rocks go for a stroll of an evening. 'Even the land at times, seems alive...'. The mountains near the Hub also attract the more spiritually inclined people, its amount of monks inspiring the name Enlightenment country. There are few places of note in the Ramtops, but this is understandable given that, although most of the land is perfectly flat, it is flat in an entirely vertical sense. Any towns are built on ledges in the faces of cliffs.
One of the larger ledges, about 1000 miles from Ankh-Morpork holds a small country known as Lancre, which is the subject of a different article. Every valley and gentle slope where a building won't slide away overnight has its own kingdom, as land that is both flat, or at least flatish, and horizontal is rare and used wherever it is found. The Ramtops is not so much a place to live, more a place to have come from, and a vast majority of Wizards, Witches and Heroes have come from around here.
Weather in the Ramtops is fairly consistent. During the Winter, the slopes are covered in snow that is yards thick. The coldness doesn't get to your bones, it just whips straight through you and freezes you to your very core. The people of the Ramtops have at least three sides of their house covered with log piles for the winter, and they don't let the fire in their hearth go out as a matter of both pride and survival. According to local proverb, The Ramtops is the place where winters go for their summer holidays. Summer is warm, pleasant, dry and brief. Spring and Autumn are cool and have rain that makes the heaviest downpour on the Sto Plains seem quite dry by comparison.