A historic steam train meanders along one of the most scenic rail routes in Germany's Black Forest.

This sculpture commemorates Edinburgh's sister city and their respective celebrity dogs.

A vast collection of rare, historical, and vintage supercomputers.

A unique market that brings together various goods and cultures.

One of the highest mountain passes in Europe has been ranked among the best driving roads in the world.

A magnificent waterfall nestled in the heart of the El Yunque National Forest.

This single-track road rewards brave drivers with stunning Scottish scenery.

This emotive sculpture was originally created for the 1878 World's Fair.

The frozen bubbles that form on the icy surface of this Canadian lake contain enough methane to create a small explosion.

These sea caves are the source of Xigia Beach's distinct aroma.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

The plants form a living library and laboratory for researchers and students at Michigan State University.

An unusual resting place built into the hill with an amazing view of Lake Como.

A surprising, but overlooked example of geology in the middle of the nation’s capital.

The last remaining bottle-shaped kilns in Scotland stand alone in an Edinburgh suburb.

Its walls are adorned with exquisite murals of the natural world, transforming it into an ecologist’s Sistine Chapel.

For decades these polar bears have roamed all around a Nashville neighborhood.

This small, unassuming, nursery plays hosts to some unique plant life.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

An outdoor urban gallery of large-scale artworks by the world's most influential street artists.

You can walk up Thailand’s naturally non-slip waterfall.

This colonial mining complex is now home to magnificent themed gardens.

This collection of promotional calendars preserves a staple of mid-century Mexican pop art.

The adorable animals return to this nature reserve every fall to give birth to their pups.