At the top of the stairs, you reach the Hypostila Hall, or Hall of 100 Pillars. These Doric columns - 6 meters high and 1.20 meters in diameter - serve to support the upper platform, but are also designed to drain rainwater to a reservoir that was to supply water to the garden city. The colorful ceilings of the Sala Hipostila are the work of architect Josep Maria Jujol, Gaudi's most creative collaborator.