But as inspirations go, it is tough to beat the opening paragraphs of "The Lure of the Wyrm," the third of four chapters in The Colour of Magic, Terry Pratchett's first Discworld book:
It is called the Wyrmberg and it rose almost one half of a mile above the green valley; a mountain huge, grey and upside down.Oh, and the denizens of Wyrmberg ride personal dragons, just like in Avatar.
At its base it was a mere score of yards across. Then it rose through clinging cloud, curving gracefully outward like an upturned trumpet until it was truncated by a plateau fully a quarter of a mile across. There was a tiny forest up there, its greenery cascading over the lip. There were buildings. There was even a small river, tumbling over the edge in a waterfall so wind-whipped that it reached the ground as rain.
Pretty amazing, eh?