The World Heritage site of Meteora, Greece, appears after sunset in early dusk. The crepuscular rays appear at the western horizon. They are the rays of sunlight that appear to radiate from a single point in the sky. These rays, which stream through gaps in clouds are diverging columns of sunlit air separated by darker regions which are shadowed by clouds. Meteora is a historic complex of lofty bizarre monasteries which are built on (or inside) giant natural sandstone rock pillars. Some are about a thousand years old. The name Meteora means "middle of the sky" or "in the heavens above".