A civilization which constructs of irregular shapes constructed of a light metal, heaped together so that they stand on each other; these structures rattle and bend in the wind or at a push, but ultimately hang together except under heavy force (such as cannonballs, falling stones, floods)
The king's palace is destroyed by a falling star, which detonates like a nuclear bomb in the center of the city. When the inhabitants grow brave enough to investigate the ruins of the palace, they find a new ruler, one from beyond the stars, emerging from the meteor.
The Water-Rift is a massive crater in the center of the desert, in the center of which sits a large, unfathomable machine that produces water. Thusly, it is a veritable paradise in the center of the burning desert, and a unique culture exists there.
The Earthblood Warrens are a series of caverns in which dwell men who live around the Earthblood Vein, a river of magma. They use the magma from the Earthblood Vein to warm and light their homes and cook their food. The Warrens are several miles long, stretching along the banks of the Earthblood Vein, and since nobody wants to walk that far, the Earthbloodmen capture large, magma-swimming serpents, which they train and ride.
There is a land far to the east that is a great, desolate, near-empty wasteland home only to barbarians, ghosts and monsters. Many nations launche expeditions to this land, seeking to find the rumored-at treasures and riches beyond it's outer fringe.
The World is actually a number of continents surrounded by oceans, which are in turn surrounded by mountains. The oceans rush off the edge of the plateau on which the World sits into the Outside...
An Atlantis-like island that rises from the bottom of the sea and brings magical technology with it.
Legends abound in some places about ancient landforms (Islands, Peninsulas, Mountains) that dissapeared long ago in towers of glowing energy. (See Any Unnatainable Glory entries for more info)
Real World: some Indians in the Amazon treat their eyes with a traditional potion applied with palm leaves. Brutally painful, the drug alters vision, giving the jungle's dense green walls greater texture and dimension. You could adapt this to desert or swamps, or other hard to navigate regions.