This building, the foundations of which measure 5,36 x 8,02 m, was built in the middle of the 3rd century BC in front of a splendid terrace. Beside the traces of wear on the inner faces of the walls, on the floor slabs and on the parapet blocks, stone masons’ marks related to the construction work as well as the two different spout cuttings on the back wall indicate that the fountain building served the Caunians through the centuries with some changes in its plan as a fountain house.
Custom laws: A lengthy inscription on the outer face of the wall which faces towards the harbour concerns the reformulated customs regulations. These were made to increase the trade of the harbour, which due to the silting of the sea was gradually losing its potential for incoming ships and thus negatively effecting the economy of the city.