4th B.C ... Poros Building Drain; Upper Fill Above Drain
5th B.C ... Poros Building Drain; Silt on Poros Slab Below Wall A
Early 4th B.C ... Poros Building Drain; On Terracotta Drain at North End
Late 5th-Early 4th B.C ... Poros Building Drain; On Roof Tile Used for Drain
