The world's longest covered bridge is a quaint and incredible wooden tunnel.

A spectacular cave and a beguiling lake.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

Thanks to both terrific preservation and historic vandalism this ancient site is known as the "Heart of Neolithic Orkney."

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

The railroad tunnel nicknamed the "Bloody Pit" for taking the lives of hundreds during its construction.

Inspiring Herman Melville and Henry David Thoreau, Mount Greylock in western Massachusetts is the highest point in the state at 3,491 feet above sea level.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

The celebrated eyesore created by starry-eyed sweethearts.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

On the waterfront of Sydney, Nova Scotia, a 60-ft. fiddle greets incoming ships.

A contemporary fresco movement illustrates the region's rich history.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

An eccentric playboy's astounding natural history collection.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.