The hills of Reims are carved out of deep galleries where renowned wine houses of Champagne hide their treasures. In almost complete silence and 90% humidity level, great wines ripen under a temperature that never exceeds 50° F (10° C). Nearly seven million bottles rest in the cellars that meander 124 ft (38 m) below the surface at the Cité du Champagne, in Aÿ. The chalk tunnels are lit with orange sodium bulbs in order not to produce heat that would disturb the development of the wines.