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

The beloved home to all publications indie, erotic, and punky.

A shining sculpture made of 3,115 lights, the number of visible stars in the Northern Hemisphere.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

All of Chicago's wood-paved streets are long gone but two alleys remain.

A monument to the art of slicing people open.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Christ's blood preserved in a Belgian town.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

Bioluminescent firefly squid light up this Japanese fishing port.

The face of a woman pushes its way through the earth.

The attic of a four-century-old canal house hides a clandestine church.

Not to be confused with the iconic New York City skyscraper, this Chicago building is a vibrant hub for artists.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."