Premise: The Cincinnati and Whitewater Canal Tunnel is a historic yet abandoned canal tunnel in the southwestern corner of the U.S. state of Ohio. Located within the village of Cleves near Cincinnati, it was constructed in 1837 as part of the Whitewater Canal system. Since the canal's closure, it has largely been forgotten, but it has been designated a historic site.
Hypothesis: The Cincinnati and Whitewater Canal Tunnel has been seen by Carl.