The eastern side of the temple is Ionic with a hexastyle portico. The eastern portico, with its six Ionic columns, supports a pediment without sculpture. The interior of the Erecthion is a scrambled mess of later substructures and remodeling which have even destroyed the foundations of the building. In one of the two inner cellas, three altars were housed, to Poseidon-Erecthonius, the hero Boutes, and Hephaestus. The other cella was dedicated to Athena and contained a wooden statue of her. In front of the statue burned a lamp that only needed to be refilled once a year. A cistern, added during medieval or Turkish times, has destroyed evidence of the Erectheis spring. Originally, the spring was supposed to give off the sound of waves, exactly like the sea. The northern porch is considered a masterpiece of Attic art. It has an Ionic colonnade with four columns and an additional column at each side. Its frieze is in dark blue Eleusinian marble and its ceiling is paneled. One panel was left out over the spot where Poseidon's trident struck the Acropolis. Beneath the panel is a pit within which three holes in the rock can be seen. The current structure of the porch was restored from a Roman restoration. East facade of the Erechthion The North Porch (from the east) North door and missing ceiling panel