the man-made enclosure of a spring, partially excavated in 1921 by sir arthur evans, was completed by j. sakellarakis in 1964. the floor is laid with pebbles, and the walls are poros-stone. evidence indicates that it was built between middle minoan ib and middle minoan iiia, destroyed during late minoan ia, and then restored and in various use afterward. the reservoir is within the palace grounds.