This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

Meant to be one of the most extravagant hotels in the world, now an eerie, abandoned architectural gem in Mexico City.

A geological oddity topped with a 2,000-year-old pagan temple.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

Elevated freight railway turned wildly successful urban park.

The first American woman to win the Nobel Prize in literature came from the foothills of Appalachia.

Near-constant high winds deform the trees on Spruce Knob, the highest point in West Virginia.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

Lake Champlain Bridge, the recently demolished and rebuilt bridge where they filmed "What Lies Beneath".

The sweetest graveyard in the world is filled with headstones for dearly de-pinted ice cream flavors.

A blend of art, antiquities, and Americana fill this museum, surrounded by whimsical, enchanting gardens.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

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

This elaborate towering structure was once famed for its revolutionary height.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

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.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Two thirds of this Montreal neon icon has survived to flash another day.

City law dictates that this mountaintop cathedral containing the heart of a saint is to remain the tallest building in town.

A Montreal deli that was so beloved that it was allowed to circumvent their laws of language.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Iconic rock formations that allow for exploration during high or low tide.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.