This monument is a stark reminder of the horrors of the Zanzibar slave trade.

In Zanzibar, a historic 19th-century palace is a reminder of the world's shortest war.

Freddie Mercury's childhood home is now a monument to the iconic Queen rockstar.

This slowly crumbling mansion was home to one of East Africa's richest and most powerful slave traders.

Over the course of its history, this tiny island has held enslaved people in transit and served as a quarantine zone. Today, it's a giant tortoise sanctuary.

This massive statue is the personification of Bavaria and the first colossal statue of the modern period composed of bronze.

A serious museum dedicated to two German comedians.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The “Thumb” of Mauritius provides a 360 degree view of the entire country.

This small group of sand dunes manages to pack in a strange rainbow of colors.

Nelson Mandela lived here with his family from 1946 until his arrest in 1962.

This center in the Rwandan capital supports women’s livelihoods while educating visitors about traditional cooking, craft making, and more.

This urban park is home to monkeys and a number of endangered plants.

These strange piles of magnetized volcanic ash travel across the desert about 50 feet per year.

A hollowed-out baobab that became the horrific final resting place of leprosy sufferers, with gruesome evidence to prove it.

Zambia's smallest national park is home to one of the world's largest annual mammal migrations.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

Hear the quietest sound from across the dome.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.