Post. Lots and lots of pots. Studying ancient ceramics is not the most exciting of research specialties, but it is surprisingly useful and informative, especially when you don’t just throw away the non-museum pieces. Amphorae, the big storage jars used throughout Greco-Roman history, can reveal trade routes, changes in demographics, extent of wealth in an area, and diet. As one would expect, Rome imported a lot of stuff, from precious metals to olive oil. For the most part, they also recycled broken pots. Except for one specific type of amphora that got thrown away. Just like the plastic now accumulating in the oceans, it got thrown into a pile and just sat there, until it literally became large enough to be a freaking mountain.
Enter an attraction that probably isn’t on many tourists’ lists, Monte Testaccio. It stands roughly 115 feet high with a base of about 220,000 square feet, which doesn’t sound very impressive until you realize it’s made almost entirely of garbage. This is the area where Romans threw all the broken and discarded amphora, to an estimated 53 million pots making up the hill. Yup, the Romans imported so much stuff, there’s an entire mountain of discarded pottery.
The majority of those 53 million pots are Dressel 20s, which look like this.
Because we have a decent database of pot types, fabrics (the actual clay and its composition), and other ceramic studies, this tells us the Romans imported a ton of olive oil from Baetica (Spain). The Dressel 20 was used for olive oil, and is a Spanish amphora.
Where it gets weird and confusing for scholars is why the mountain even exists. There are no other mountains of discarded pot types, or for wine and fish sauce imports, so why Dressel 20s and olive oil? It seems the proximity to the Horrea Galba might play a role, since this is where the Romans had their state olive oil reserves stored. The specific design of the Dressel 20 might answer why the mountain exists. Giving a little more credit to the Romans than I did earlier, they were innovative and fairly good at recycling. Broken pots were often reused for all sorts of things, including drain pipes, roof shingles, and “scratch paper”—the Greeks used pot sherds for voting on things like ostracism, for example. For comparison purposes, here’s the whole Dressel chart—like the world’s worst police line up.
It’s possible the reason this mountain of Dressel 20 pots exists is because the pots did not work very well for these other purposes, being more “globular” than other types. Still, Dressel 20s had a wide disbursement and use throughout the Roman Empire, but there aren’t any other mountains of discarded olive oil containers. No mountain in Athens, Alexandria, or anywhere else.
So why do we have this Monte Testaccio? Who the fuck knows. To my current knowledge, the issue is still open, so feel free to throw your own theory to the mix. Pottery studies are a fairly recent addition to Roman archaeology, and research on the Roman economy, so there’s still a lot of work to be done. Fortunately, the existence of the mountain means nobody will be bitching about not having enough Dressel 20s to study any time soon.