In this world, gravity is not absolute law. Given the right circumstances, one can defy gravity and fly through the heavens.
Even the ground itself is less shackled by gravity, creating whole continents that resemble mountains on a much larger scale. The rich variety of altitude creates a fully three-dimensional world in which the vertical dimension is just as important as the two lateral dimensions.
A unique biological landscape has formed to complement the topology, with widely varied life to be found above, below, in, and around every part of the world. Large spiders can be found living on the sides of many long cliff faces, floating whales create a spectacle soaring through the skies, and the sapient species of the world value climbing as much as running.
The topography also creates prohibitively violent storms on the surface of most oceans, preventing most inhabitants from traveling by sea. Instead, they travel using airships, held aloft by envelopes full of heated, gravity-defying substances commonly referred to as elevators.