This paper craft is a Modular Terrain, designed by Sean Kelly. You can use it for your paper diorama or RPG game. The Modular Terrain series is a set of interlocking 32cm x 32cm panels (2 cm overlap) meant to replicate realistic elevation changes without the need for separate loose sections laying atop a flat surface like a table.
The design accommodates for both depressions and elevations with equal ease, in an inexpensive, light and durable format. There are five sections in this set, which may be arranged in any order. [Via Sean Kelly]
You can download the template here: Modular Terrain for Diorama and RPG Game Free Paper Craft Download