Temple F, the oldest and smallest of the three, was built between 550 and 540 BC on the model of Temple C. Of the temples it has been the most severely spoliated. Its peristyle was 24.43 x 61.83 metres on a 6 x 14 column pattern (each 9.11 metres high), with stone screens (4.7 metres high) in the space between the columns, with false doors painted in with pilasters and architraves – the actual entrance was at the east end. It is not clear what the purpose of these screens, which are unique among Greek temples, was. Some think they were intended to protect votive gifts or to prevent particular rites (Dionysian Mysteries?) being seen by the uninitiated. Inside, there is a portico containing a second row of columns, a pronaos, a naos, and an adyton in single long, narrow structure (an archaic characteristic).