The structure is made mostly of concrete and is comparatively small, enclosed by thick walls, with the upturned roof supported on columns embedded within the walls, like a sail billowing in the windy currents on the hill top. In the interior, the spaces left between the walls and roof are filled with clerestory windows, as well as the asymmetric light from the wall openings, serve to further reinforce the sacred nature of the space and reinforce the relationship of the building with its surroundings. The lighting in the interior is soft and indirect, from the clerestory windows and reflecting off the whitewashed walls of the chapels with projecting towers.