Solid wooden beams frame and support the slate roof, and windows with louvered covers allow fresh air to circulate. A sturdy shelf holds items that need not be kept as cold. Thick stone walls built into the side of the hill protect the water source and provide cold storage. Cold spring water flows out of the hill and then around the outer trough, exiting at left. Stoneware crocks protect perishables as they chill in the spring water.