Mentioned in another thread: I created a continent in my D&D world based on a theme that came from one of Terry Pratchett's books...
And I am curious about that continent.
It comes from the book Lords and Ladies. Have you read it? For those that haven't, some ding-dongs, believing the fables about elves find out the elves are confined, work to break their imprisonment believing the world will be made better... but these elves are not like the stories. They are cruel and vicious, believing themselves to be the superior race, and they are very magical.
For my D&D world, I created a race of "elder elves" that were one of the first races, pre-dating the rest of the elves (which all still exist, though drow are albino instead of black-skinned) and all the rest. They were imprisoned thousands and thousands of years ago, the reasons for which will become clear, but within the last few hundred some well-meaning schmuck (a deity no less) thought he'd solve certain imbalances (as he saw it) in the world by releasing them. Things went poorly. These elder elves are chaotic evil, very predatory, have loads of inborn magical ability... and no desire to trade. They do not take prisoners per-se, using illusion and enchantment to trap prey if they are not hungry, keeping them ready for when they are. They kill, eat and keep the loot.
After their release, they took over a continent with thriving civilizations... and what is left of those are about a dozen walled cities, the walls of each 200' or more high and 50' thick. The very few of these not coastal are very isolated. There are a few isolated cities/towns up in the mountains. There is a normal grey elven city (with many refugees composed of the other elven races), a dwarven city, a few gnome and halfling villages hidden here and there. The elder elves appear to avoid mountainous terrain, and what is not mountainous or behind those walls... is basically theirs.
The whole continent is forest, trees growing to enormous sizes. Oaks, maples, pines, fruit trees... everything reach the size of sequoias... and sequoias reach the size of sky-scrapers. The whole place is lush with vegetation, food to be had... and psychotic elves riding around on hunting cats and dire wolves hunting anything that moves, the more difficult the prey the better.