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

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

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

A New York–based physician returned home to Spain to build his own elaborate monument to Christopher Columbus.

This ancient amphitheater was restored in the early 1990s.

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

An abandoned Roman salami factory has found new life as an art space home to 200 squatters.

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

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

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

Barcelona's only remaining tram system takes riders to the Tibidabo funicular.

Numerous sculptures set along hiking trails symbolize and idealize the relationship between man and nature.

The location of the last witch trials of Italy, known as "The Salem of Europe."

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

The metal leaves on this tree are engraved with the names of Holocaust victims.

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

A fascinating insight into daily life in the Eastern Bloc.

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

In the foothills of the lesser Caucasus, a centuries-old fortress still stands.