The fountain house was built during the first century BC as a U-shaped portico with a courtyard open towards the south. The back wall of the west portico was rebuilt during the early 2nd century AD after an earthquake and at the same spot. The south side was closed off by a wall with a stairway. Near the beginning of the 3rd century AD the fountain house was incorporated into an esplanade surrounding it on three sides. After the earthquake of 518 AD the courtyard was partly filled and the water was distributed by terracotta pipes over the city.