A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

At this 16th-century monastery in rural Bulgaria, visitors can also spend the night.

A massive cave once a secret military base is now home to thousands of bats.

Rebuilt several decades ago, its striking murals prevent it from being reconsecrated as a church.

An homage to the medieval rulers of Bulgaria.

Said to be the only museum in the world dedicated to the most classic of all blooms, the rose.

"Holy Wisdom" overlooks the city that became its namesake.

A mountain pass in Bulgaria's Balkan Mountains was the site of four historic battles.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

UNESCO-protected ancient burial ground.

A striking symbol of the Bulgarian capital.

Over 60 species of birds inhabit this colorful aviary park in South Africa.

An ancient impact crater on the outskirts of Pretoria.

Mined to a depth of 240 meters with a perimeter of about 1.6 km, the largest hand-dug excavation in the world.

This road winds through the steep coastal cliffside offering spectacular views for those who brave the drive.

Caves that can't seem to quit producing the remains of prehistoric humans.

Home to some of the oldest hominid fossils ever found.

A safari-themed castle in the South African bush with the largest maze in the southern hemisphere.

Largest cave system in Africa.

Raging waters have created a strange geological site that looks like something off of a progressive rock album cover.