Photo: Getty Images
The largest cave in the United States has just gotten a little bit bigger.
Researchers at Mammoth Cave National Park recently discovered an additional 8-mile long passage. This means that the cave system is now 420 miles long.
"When it comes to discoveries in Mammoth Cave, there truly is no end in sight!" an Instagram post from the park reads.
The passage was found by Cave Research Foundation volunteers who help map and survey the caves. They use compasses, measuring equipment, and other specialized tools to record data about the cave.
The collected data is used by the national park to better manage the caves and understand where things like prehistoric artifacts, animals, insects, and minerals are located underground.
Park rangers and researchers are always discovering new things about Mammoth Cave. Recently, the park shared a photo of how fog can form underground under certain weather conditions.