Monte Testaccio is a mound made up of shards of broken pottery covering about 220,000 square feet, holding 760,000 cubic yards of broken pottery vessels, known as amphorae, which were used to transport olive oil.
Excavations are still in progress, but the most recent finds indicate it may have originated as early as 140 A.D. Archaeologists agree future excavations could reveal that it could have been even earlier.
The easternmost side is the oldest of the triangular shaped, terraced mound. Paths were constructed by using smaller shard pieces throughout the four stepped terrace levels to enable the continuation of amphorae disposal and the height of the hill.
Most of the pottery shards are those of a Dressel 20, the one gallon sized amphorae from Baetica in what is now the Guadalquivir region of Spain, but remains from Tripolitania, now Libya, and Byzacena , now Tunisia, have also been found.
Why the mound was created is still a mystery.
It has been established that these were bulk containers used for shipping olive oil, but why were no other types of shipping containers added to the mound?
The Romans also imported grain and wine, but as of yet, very few of these types of containers have been found. The Dressel 20 amphora did not easily break into the small pieces needed for recycling into concrete, which could be the reason they were simply discarded.
Another possibility is that the residual oil left on the shards would have reacted poorly with the lime content used when making the concrete. José Remesal of the University of Barcelona and co-director of the Monte Testaccio excavations believes the hill contains the remains of over twenty-five million amphora, and his team is recovering over a ton of pottery every day.
They are searching for any type of identification that could be stamped, painted or carved into the clay.
Most amphorae used during the time noted the weight, information about where the oil originated and names of the people who bottled and weighed the shipment which is indicative of a stringent inspection system used to control trade.
The empty weight, as well as the full weight, was recorded and the names found give insight into the Roman commercial structure. Many list family businesses such as “the two Aurelii Heraclae, father and son” and “the two Junii, Melissus and Melissa” as well as small groups of men “the partners Hyacinthus, Isidore and Pollio” and “L. Marius Phoebus and the Vibii, Viator and Retitutus”, who were most likely members of joint ventures of skilled freedmen.
The team is also able to identify that the state authorized the shipment of the oil and if the oil was for the military or civilian use.