From golf course, to amphitheaters to wild life preserves … there are some pretty amazing things that have been done with reclaimed mine sites, but a former limestone mine in Kentucky might be the coolest of all.

The Courier Journal reports that the 320,000 sq ft facility in Lousiville has been converted to an underground bike park with more than 45 trails ranging from very challenging dual slalom and BMX trails to easier rides for the family.

The facility has gained national attention, including a visit from NBC corespondent Kevin Tibble that was aired on the TODAY show.

Tom Tyler, who co-owns the former mine, now called the Mega Cavern and the other owners started out using the mine’s nearly one million square feet of underground space as a dumping site for dirt and rock in the early 1990s, and later as a storage site for businesses. About five years ago, they installed zip lines in a section of the mine and in recent years set up a drive-thru underground Christmas light show that draws long lines of cars during the holidays.

Two decades of dumping gradually built the floor up over time, and gave the owners plenty of earth to work with. Tyler said there were requests from visitors and bikers to build a bike park in the mine.

Looking around the vast space spread over five football fields, with dirt trails unfolding in every direction under a 35-foot-high ceiling, the course has the breadth and feel of an outdoor space.

Read the full story, and view pictures and video of the park at the Courier Journal website or at the Louisville Mega Cavern website.