A 2,000-year-old Roman water channel is still flowing today. This remarkable underground aqueduct lies beneath the Smyrna Agora in Izmir, Türkiye. Built in antiquity, it once carried fresh spring water to the city’s baths and fountains. The stone arches remain exceptionally well preserved, and the main channel is large enough for a person to walk through. Even after two millennia, water continues to run through the system and is now used to help irrigate the modern archaeological site.