Divers and archaeologists are uncovering remarkable finds within the Kupa River in Sisak, Croatia. The riverbed holds the submerged remains of Siscia, an ancient Roman city, along with an exceptionally well-preserved 1,800-year-old Roman barge. To date, over 9,000 artifacts have been recovered from this single location, offering invaluable insights into Roman life and trade. The discovery includes remnants of a Roman bridge, further illustrating the city’s infrastructure. These findings highlight the rich historical significance of the region. Ongoing excavations promise to reveal even more about this lost city and its people, making the Kupa River a crucial site for archaeological research.