LOUISVILLE, Ky. (WHAS11) -- According to Trip Advisor the Mega Cavern has passed Churchill and the Derby Museum as the city's number two attraction.
Only the Louisville Slugger Museum and Factory beats it.
The Mega Cavern is located underground near the Louisville Zoo, and the popular zip lines have only been open since last summer but they're getting national attention.
"But we've been on Travel Channel, Discovery Channel...this is very unusual because its the only place in the world where you can do a zip line course underground," Jim Lowry, Mega Cavern owner, said.
Lowrey said the Mega Cavern is setting aside some extra space for a possible expansion in the future.