We visited Mammoth Cave National Park in Kentucky. It is notable as the longest cave system in the world, with over 400 miles of passages.

Visitor center:

Mammoth cave has several guided tours available. We did the “Domes and Dripstones” tour, which required taking buses to a cave entrance:

Down into a sinkhole:

Cave entrance:

Looking down:

Underground ranger talk:

Not too bad a picture of me:

Lots of steps:

Historic graffiti:

Very flat cave ceiling:

Ranger talk area:

More steps:

The “Frozen Niagara” formation:

Vertical panorama of a dome:

An interesting cave, but we’ve seen nicer-looking ones. Just shows that size isn’t everything.