A huge, ancient sewer has been unearthed during archaeological excavations in Turkey - and it's still in working order. Expert archaeologists discovered the sewage system in the historic city of Stratonikeia in Muğla, and have reportedly estimated that it is around 2250 years old - dating back to ancient empires. One section of the system was a massive sewer beneath a theatre, that is so big human beings can even walk through - per the Jerusalem Post. The system works by moving water from beneath the theatre towards a nearby stream and amazingly it still does the job - something that the archaeologists who discovered it were excited to learn.