Flatterland is a 2001 book written by mathematician and science popularizer Ian Stewart about non-Euclidean geometry.

Topology and hyperbolic geometry are also discussed, as well as the Projective "Plain" (complete with intersecting "lions") and the quantum level.

Hopper and Victoria also visit the Domain of the Hawk King to discuss time travel and the theory of relativity.

The dashed red line indicates the path of the portable white hole (clockwise).

Ian Stewart often includes puns and topical references in his popular writing, and Flatterland is no exception.