The Temple of Apollo, 7th century BC. It is a peripteral Doric temple (60,32m X 23,82m) with 6 pillars on the short sides and 15 on the long ones. It was rebuilt in the late 4th century BC after a fire. No one was allowed to enter the most sacred area in the middle because it contained the “omphalos” which was thought to be the centre of the world.