An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Located in the thermoelectric factory that once powered the entire city, this Portuguese museum is shockingly fascinating.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

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

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

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

The world's oldest bookshop still in operation.

An early work of the architect Álvaro Siza Vieira, these swimming pools blend into the beach.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

The bookstore with bookshelves built into unlikely places.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Hydraulic systems in an ancient underground Iranian city.

This deceptively salty lake looks like blushing pink lemonade.

An Australian lake whose pink hue defies scientific explanation.

Where Cusack's record store from the film "High Fidelity" was located.

A military museum and library dedicated to the citizen soldier.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

A Museum of Holography frozen in 1974.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.