LOUISVILLE, Ky. (WDRB) -- The longest cave in the world is now even longer.

Mammoth Cave National Park announced on Sunday that the Cave Research Foundation found eight new miles of the cave system from mapping and exploration.

The cave now has 420 miles of known passages.

The national park is around 95 miles south of Louisville. It's open for daily tours, masks are required for everyone in buildings and crowded outdoor spaces.

To plan a visit, click here.

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