Dungeonstone is a manufacturer of miniature terrain in 25 mm scale designed for use by miniature and roleplaying gamers. The terrain is designed for fantasy or medieval roleplaying. Terrain pieces are cast in light grey but painted versions can be ordered.
From Dungeonstone website:
Our miniature terrain has been developed over hundreds of hours of sculpting and design and is perfectly suited for role playing games such as Dungeons and Dragons with a 25mm scale of 5 feet = 1 inch.
Our dungeon terrain pieces are designed to allow the GM to create the most impressive experience possible by adding a 3D landscape which has the look and feel of an actual stone environment.
These highly detailed models are each made from a resin and carbon infused diestone composite material which provides
durability and will hold up to years of handling and play.