A storage facility for stackable trolleys, as in a supermarket, comprising a unit, such as a display unit against a wall or forming an island, which has a trolley inlet to its interior spaced from a trolley outlet, each adapted to pass one trolley at a time inwards or outwards, and a conveyor for transferring an introduced trolley to the back of a stack and for advancing the stack to release a trolley through the outlet on demand, particularly by action of a coin-freed mechanism. The conveyor is a belt which lifts the front end of a trolley frictionally to drive it on its rear wheels along a guide, while permitting slip to occur beneath a stationary stack of trolleys on demand. In order to encourage trolley return, introduction of a trolley at the input releases a coin in repayment for the coin used to effect trolley release.