The tholos chamber or false dome, about 2.5 meters wide, fits perfectly with the trapezoidal shape of the stairwell and is composed of ashlars forming concentric circles; the latter shrink as you proceed towards the top of the chamber, which ends with a circular light of 35 cm and a height of 7 m.
Currently the water has a constant level of 50 centimetres, as consequence of the construction of a drainage channel built during the excavation campaign to allow the visit inside the structure every day of the year. The outer part of the temple differs from the inner part due to a less attention to detail.
However, the artistic component is not lacking. From the top you can admire a remarkable fence in the shape of a keyhole that serves as a frame and has stone seats on the inside. The exterior, elliptical in shape, measures 26 x 20 m and encloses the entire structure. The sacred well, while presenting characteristics similar to those of the other specimens present on the island, stands out for its considerable size, excellent condition, but above all for the highly refined construction technique.