The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

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

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Brussels' favorite peeing boy has a sister.

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

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

A massive Montreal stadium that has seen nothing but trouble since its inception.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

There must be a pun in this haystack somewhere...

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

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

Climb inside an iron crystal magnified 165 billion times its normal size.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

At 207 feet, one of the world's longest continuous escalators.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

A little sculpture with a large wardrobe.

The caldera of this mini-volcano has been turned into a naturally heated mud bath.

Unparalleled stargazing, one of Colombia's best observatories, and a swimming pool can all be found in the middle of this ancient tropical forest.

Cathedral carved out of salt, located a mile below the earth's surface.

A 10 million-ton rock once worshiped by the Tahamies Indians, accessed by an astounding staircase.

Largest monument in Colombia depicts 14 lancers who drove back an army.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The celebrated eyesore created by starry-eyed sweethearts.