Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

Volcanically heated hot springs.

This black shoreline is made up of exploded lava particles.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

This fairy-tale, neo-Gothic church in the Azores is a world of magical realism.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

Kenya’s oldest town is more than 700 years old and home to 6,000 donkeys.

After sunset the heart of Zanzibar's historic Stone Town neighborhood transforms into a culinary playground.

The oldest known university in the world is in Fez, Morocco.

Traditional 11th-century outdoor tannery.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

The world's largest piece of copyrighted artwork.

On a former island, this old fortification once used to protect the Boston Area and started Edgar Allan Poe in his military career.

From bench to vandalism to art, this silly prank seat was funny enough to become permanent.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

The site of Paul Revere's historic two lantern warning.

Two thousand artifacts from around the world collected by one woman who loved to travel.

A beautiful Victorian-era cemetery, complete with a miniature village.

An enormous, inside-out glass globe built in 1935.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A 200-year-old building in the French Quarter that was to be Napoleon's home in the New World.