 It was an open-air precinct built in the shape of a quadrilateral, and its principal feature was Athena's sacred olive tree.In the shade of the olive tree stood an altar to Zeus Herkeios (Zeus of the Court).The southeast corner A door in the lower storey of the western wall of the Erechtheion provided direct access between the Pandroseion and the Erechtheion's interior; yet another doorway also connected the Pandroseion to the north porch of the Erechtheion.