Abstract: A tamper proof fire hydrant which may only be operated by the application of pressurized fluid. The pressurized fluid engages the fire hydrant and travels through a pathway in the upper portion of the fire hydrant. The pressurized fluid engages a turbinelike impeller and then the pressurized fluid pressure rotates the impeller, the impeller is connected to a worm gear and turns the worm gear which then operates to open the hydrant's water main valve. Later the flow of fluid is then reversed in order to turn the turbinelike impeller in the opposite direction thereby causing the worm gear to operate to close the hydrant's water main valve. A cylinder and piston may be used in place if the impeller and worm gear, to open and close a water main valve in response to the application of pressurized fluid to the fire hydrant from an external source.