A small island abbey is the final resting place of many medieval Scottish monarchs, including the real Macbeth.

Former abode of notable poet, complete with literary references and stories of ghosts.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

A New England curiosity cabinet, one hundred years on.

Every January 6, young men dive into Spring Bayou in search of a cross and a year's worth of maritime blessings.

This Roman amphitheater is said to be King Arthur's legendary Round Table.

Even Henry David Thoreau found this glacial pothole irresistible.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

Cheap art and political theater in Vermont.

A coastal rock outcrop with mysterious inscriptions variously attributed to Native Americans, Portuguese, Phoenicians, Norse, and more.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

The massive machine creates cracking displays of indoor lightning.

Surprisingly aquamarine waters fill deep lakes formed at the end of the last ice age.

The remnants of the fortress that saved Georgia from the Spanish still stand guard on their swampy island.

The “American Gothic" artist's largest works hang in an Iowa State University library.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

The ancient tomb acts as a calendar that keeps perfect time.

Twice a day this ancient path disappears with the tides, leaving the Holy Island of Lindisfarne out to sea.

The remains of a deserted 1800s farming community can be found in Little River State Park.

Scotland's oldest medieval bridge is also among the last reminders of early medieval Aberdeen.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.