These 2000 year old remains of a Roman aqueduct are hidden inside a hotel lobby.

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

This fountain was designed to honor the man who helped bring water to Barcelona.

An open-air "garden" of mural art that changes weekly.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

An early 20th-century bullring converted into a modern shopping center.

This colorful statue welcomes visitors to a Barcelona park.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

A historic structure inspired by Roman, Muslim, and Jewish bath houses.

Designed by Gustave Eiffel before his famed tower.

Kissing the ass of this stone lioness has become a rite of passage in the city of Girona.

The design of this seemingly translucent two-story tower in northwest Cambridge was inspired by an optical illusion.

An extraordinary library and archive dedicated to the history of the Arctic and Antarctic poles.

An oasis of shade and color amidst the bustle of the old city.

The most gigantic, swoony, intimidating trio of fingers in all of antiquity.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

The world's oldest map of the holy land gives us a fragmented glimpse of the layout of biblical nations.

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

This flagpole ranks among the world’s tallest and can be seen from three countries.

Known as the "Valley of the Moon," this Jordanian wadi is one of the most amazing desertscapes on Earth.

Children's hospital in London that operates on royalties received from Peter Pan, which J.M. Barrie signed over in 1929.