One of the hideaways in and around America's Stonehenge used by the Pattee family to hide runaway slaves making their way up the Underground Railroad to Canada in the early 19th Century (if you believe the stories)
Thanks, fellas. jtk: In answering your question I did some research (rather than relying on what's told at the tourist trap). Turns out Mr. Pattee was an Abolitionist, and the use of the "Pattee Caves" as a stop along the Underground Railroad by runaways coming from Boston on their way to Canada is as well documented as any other information on what was essentially illegal activity at the time (ref: "Slavery & the Underground Railroad in New Hampshire" by Michelle Arnosky Sherburne). Artifacts such as manacles have also been found on-site. I have no reason to doubt the story.