Abstract. Terrain generation algorithms have an important role in video games: they can provide a realistic scenario for the game experience, or can help keep the user interested in playing by providing new landscapes each time he plays. Nowadays there are a wide range of techniques for terrain generation, but all of them are focused on providing realistic terrains, often neglecting other aspects (e.g., aesthetic appeal or presence of desired features). This paper proposes a new technique, Genetic Terrain Programming, based on evolutionary design with GP to allow game designers to evolve terrains accordingly to their aesthetic feelings or desired features. The developed application produces Terrains Programs (TPs) that will always generate different terrains, but consistently with the same features (e.g. valleys, lakes). This characteristic will allow game designers to endow games with programs capable of generating different coherent landscapes each time users run the game.