Cave Creek Campground in Oregon Caves National Monument and Preserve offers an amazing opportunity to camp in an old-growth forest campground. The campground has plenty of shade and tree cover.

Nov. 1-March 31, 9 a.m.-4 p.m., $6-$12. Mark Twain Cave and Campground, 7032-7037 County Road 453, (near Highway 79), Hannibal, 573-221-1656, http://www.marktwaincave ...

The narrow paths flowed up and down. The group spent four days wading through hip-high waters before traversing through and camping in soaring caves. At the end of Hang Son Doong stood the Great ...

The surface of Mammoth Cave National Park encompasses about 80 square miles. No one knows how big the underside is. More than 365 miles of the five-level cave system have been mapped, and new ...