Calling all cave huckers, Kentucky’s Louisville Mega Cavern is about to open as a 320,000-square-foot underground bike park. It will feature 45 trails, a BMX park, pump tracks, dual slalom and singletrack all in a former limestone cavern 100 feet sub-surface. The park is slated for a “soft opening” on Monday the 9th, and reservations are requested in advance. Bring your own bike for now, rentals will be set up as early as next month.