1 - Internal mole. 2 - Claudian portico. 3 - Harbour for smaller boats (so-called "Darsena").
4 - Porticus Placidiana. 5 - Small lighthouse. 6 - Baths. 7 - Small theatre. 8 - "Imperial palace".
9 - City wall. 10 - Colossal statue of Trajan. 11 - Temple of Liber Pater. 12 - Villa Torlonia.
13 - Aqueduct. 14 - "Temple of Portumnus". 15 - Defensive cross-wall with towers. 16 - Horrea.
17 - Barracks of the fire-brigade? 18 - Bishop's palace. 19 - Tower. 20 - Temple.
21 - Church of St. Peter and Paul. 22 - Foro Olitorio. 23 - Grandi Magazzini di Traiano.
24 - Grandi magazzini di Settimio Severo.
Plan by Jan Theo Bakker, after R. Meiggs, Roman Ostia, Oxford 1973, figs. 5 and 6.