The Roman aqueducts brought fresh water into the cities, but the Roman sewers took human waste out of them. The Roman baths and the sewer systems suggest that the Romans took personal hygiene and public health very seriously. Rome and other major Roman Empire cities had a very complex network of sewer tunnels and drainage systems. While dumping the waste into the river Tiber isn’t the best sanitary solution, there is no way to dispute the fact that the Roman sewage system has changed the world. In fact, it was so advanced that it remained virtually unchanged until the 19th century.