When people think of Rome they think of the Coliseum, but this year the Coliseum has an ancient athletic rival: the Circus Maximus. After years of excavations and improvements, Rome’s charioteer stadium—the ancient equivalent of a NASCAR track—is finally open to the public. But however you feel about the races there’s plenty of interesting stuff to be seen here; the ancient world’s largest shopping mall, among them. But for my money one of the most interesting features is the well-preserved and very public ancient latrines, which operated with water siphoned from the nearby aqueduct. Bear with me. They’re a testament to Roman engineering and evidence that even though the Romans had a highly developed sense of decorum, they didn’t mind emptying their bowels en masse.

The multi-seat bathrooms (foricae) at the Circus Maximus are not unique; on the contrary, they existed all over the place. There is one at Ostia Antica, the ancient port of Rome; another at Ephesus in Turkey; another in Timgad, Algeria; and another at the emperor Hadrian’s second-century villa in Tivoli, Italy. They are everywhere. What they have in common is benches punctuated by keyhole-shaped openings that faced inwards and that usually sat about eight to twenty people. It seems that most people expected to do their business cheek-to-cheek.

Despite their proficiency with plumbing and engineering, the Romans did not invent the toilet. According to Cambridge archeologist Augusta McMahon, the first simple toilets were Mesopotamian pits, about 1 meter in diameter, over which users would squat. The pits were lined with hollow ceramic cylinders that prevented excrement from escaping. Approximately 1000 years later the Minoans invented the flush. The first flushing toilet, excavated at the palace of Knossos in Crete, washed waste from the toilet to the sewer. By the Hellenistic period large-scale public latrines brought toilets to the effluent masses.