A new underground bike park called Mega Cavern is being built in an abandoned limestone mine in Louisville, Kentucky. The owners say it will be the largest indoor course in the U.S., at 320,000 square feet.
Co-owner Tom Tyler said that he and the other owners started out using the mine as a dumping site for dirt and rock in the early '90s. Over two decades, the dumping built the floor up. Tyler said they got requests from bikers and visitors to build a bike park in the mine.
The course is expected to be open to the public in March.