by the end of antiquity. Above the columns followed the architraves with the frieze. The frieze is especially famous as it housed the impressively monumental heads of Medusa. The entrance was at the east side. With a pronaos of three rows of four columns, the approaching visitor passed through a regularized grove formed by the columns. The door usually leading to a cella was replaced by a blank wall with a large upper opening through which one could glimpse the upper part of the naiskos in the inner court (in inscriptions the inner court is referred to as "sekos" or "adyton"). The impassable threshold of this door stands 1,5 meters above the floor of the pronaos, while the entire door reaches a height of 14 meters. The entry route lay down either of two long constricted sloping tunnels built within the thickness of the walls and giving access to the inner court, still open to the sky but isolated from the world by the 25 meters high walls of the sekos. This was the location of the oracle spring, the laurel tree and the naiskos with the cult statue. The foundations of the naiskos are 8,24 meters wide and 14,23 meters long. This Ionic prostylos was built around 300 BC. It is famed because of the superior high quality of its ornamentation. The naiskos with the cult statue of Apollo is depicted on Imperial coins of Miletus. The sacred oracle spring was not situated in the naiskos, but in the eastern half of the sekos. It was found beneath the early Byzantine church. The inner walls of the sekos were articulated by pilasters. The capitals of them are ornamented with griffins and flowers. Among them a long frieze with griffins decorated the whole sekos. Between the two tunnel exits in the sekos a monumental staircase leads up to three openings into a room whose roof was supported by two columns on the central cross-axis. Among these three doors were placed two Corinthian half columns, whose spectacular capitals originally survived but during the First World War they were unfortunately destroyed. The room with the two central columns opened to the east to the great impassable portal. To the north and south of this hall two stairwells existed. In inscriptions they were called „labyrinthoi", probably because of their ceiling decoration showing a meander pattern. These labyrinthoi lead to the roof of the