Dr Barnes' $25 billion private collection of art and arboretum.

A daily replay of the experiment that proved the rotation of the Earth.

The castle still holds traces of the abandoned Roman fort it was built atop.

This castle tower in Wales leans at a steeper angle than the Leaning Tower of Pisa.

In 1977, an eccentric book lover formed a micronation for book lovers.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The world's oldest bookshop still in operation.

One of the world's southernmost bars.

This remote stretch of sand is a penguin lover's paradise.

Final resting place of Antarctic explorer Ernest Shackleton.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.