A demountable, modular roll container comprises a plastics base (1) with wheels (13) (or castors) attached and two, three or four side plastics panels (2, 3) which lock into the base (1) with adjacent panels (2, 3) locking into each other. One or more shelves (18) lock into and stabilize the side panels. The whole assembly makes a modular two, three or four-sided container on wheels, with one, two or more compartments.