This rare basalt crater lake is used to study the Moon and Mars.

Once an indicator of social class, the color blue has come to define this city on the edge of the Thar Desert.

Deep in the Thar desert, a temple crawling with thousands of holy rats.

This elegant neoclassical garden is a peaceful oasis in the middle of the Nepalese capital.

This grand Pakistani mausoleum can only be accessed via an almost 1,000 foot long alleyway.

An obelisk designed in memory of the soldiers from the city and district who fought in The Great War.

This temple contains what might be the world's oldest optical illusion.

In Kazakhstan, a colorful cathedral with many lives once survived the most powerful earthquake in the region.

An abandoned Soviet-era mining town in the mountains of South Kazakhstan.

Underwater restaurant at the coral reefs of Eilat.

This clock is an architectural flourish that stands out as a landmark among a unique Israeli German community.

Israel's first dedicated natural history museum is home to 5 million specimens and still growing.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

Some believe that this ancient mural depicts technology far ahead of its time, but in reality it's nothing quite out of place.

One of its engravings is believed to be among the first representations of medical and surgical instruments.

Where artisans use centuries-old techniques to build traditional Arabian ships.

This series of Armenian caves held the oldest brain, shoe, and winery in the world.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

Fantastic lake on the heart of a fault line.

A Turkish ghost town abandoned in a population exchange with Greece.

A section of the long chain that blocked enemy ships from entering Constantinople.

A peculiarly shaped brass sculpture hidden in a courtyard in central Lviv

A two thousand year old brothel uncovered in Northern Greece.

Cave on extinct volcano, once home to famous mathematician Pythagoras.