Regio XIII Aventinus

[1] In extent, this region was bordered by the Tiber River to the west, the Circus Maximus to the north, the Vicus Piscinae Publicae and the Via Ostiensis to the east, and the Aurelian Walls to the south.

A measurement taken at the end of the 4th century recorded that the perimeter of the region was 18,000 Roman feet (approximately 5.3 km).

Regio XIII also contained the Emporium, the first port built on the Tiber, and attached to the port were the warehouses of the Horrea Galbae,[4] built around the tomb of Servius Sulpicius Galba, while nearby was the Forum Pistorium.

The region also possessed two unusual features still present today: Monte Testaccio, an artificial hill, and the Pyramid of Cestius.

[5] At the turn of the 5th century, the Regio was divided into 17 vici (districts) and 2,487 insulae (blocks).