The Porta San Paolo is one of the southern gates in the 3rd-century Aurelian Walls of Rome. The Via Ostiense Museum is housed within the gatehouse.
The original name of the gate was Porta Ostiensis, because it was located of the beginning of via Ostiense, the road that connected Rome and Ostia where functioned as its main gate. Via Ostiense was an important arterial road, as evidenced by the fact that upon entering the gate of the same name, the road split, with one direction leading to the famous Emporium, the great market of Rome.
The gatehouse is flanked by two cylindrical towers, and has two entrances, which had been covered by a second, single-opening gate, built in front of the first by the Byzantine general Belisarius (530s–540s).
The structure is due to Maxentius, in the 4th century, but the two towers were heightened by Honorius. Its original — Latin — name was Porta Ostiensis, since it opened on the way to Ostia. Later, it was renamed to the Italian Porta San Paolo, because it was the exit of Rome that led to the Basilica of St. Paul Outside the Walls.
In 549, Rome was under siege; the Ostrogoths of Totila entered through this gate, because of the treason of the Isaurian garrison. On 10 September 1943, two days after the armistice between the Allies and Italy had been agreed, Italian military and civil forces tried to block German seizure of the city, with 570 casualties.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.