How big is the carousel in Cincinnati and how many times to walk around to get a mile

Assuming the distance across the carousel is 36' (diameter) the distance around (circumfrence) 2piR is 228 feet. Allowing an additional 10% clearance around the outside to walk, you would walk 5280 feet (1 mile) in 42 revolutions.

I go there on a regular basis, weather pending. There are no distance markers, that I have seen. The concrete walkways might be a 2½ mile loop. Strictly a guess.