This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.

A historic covered bridge, only one of two remaining in North Carolina.

This replica of the Greek structure is in the heart of Nashville.

This rare polygonal meeting house is rumored to be built in a circle so that the devil has nowhere to hide.

This New England covered bridge is home to the tale of a jilted lover known to haunt the area.

The fifth-longest natural arch in the world, and the longest outside China.

A striking, menacing sandstone peak towering above a landscape that's equal parts Mordor and the Moon.

Oddly shaped rock formation, misassociated with a nearby utopian community.

This quiet park's strange sedimentary spires were named after Kodak's color film.

Despite its name, this route in southern Utah offers a heavenly day trip.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

This simple home was the beginning of a long journey for the iconic Western film star.

This fairy-tale, neo-Gothic church in the Azores is a world of magical realism.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

The former seat of power for the Balliol dynasty.

A carved bench marks the Scottish cave that inspired the classic adventure novel "Treasure Island."

A red-brick beacon stands against the tempestuous Atlantic, on the windiest site in the United Kingdom.

An 18th-century lighthouse built on a 16th-century castle is now a monument to the maritime beacons of Scotland.

A six-ton wedding present for the King of the Scots.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

The mysterious megaliths have enchanted and intrigued visitors for thousands of years.