This lake in northwest Iran has started turning from green to red more frequently than scientists are comfortable with.

The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

In this tiny Iranian town playing on the roof isn't just encouraged, it's the only place to go.

17th century mosque for Shah Abbas' harem.

Hydraulic systems in an ancient underground Iranian city.

Modern-day cave dwellers carve elaborate homes out of volcanic debris.

The palace of the King of Kings, burned by Alexander the Great.

This beautiful system of tunnels built into natural rock serves as a centuries old plumbing system.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

This ruined fortress was the stronghold for a persecuted medieval leader and his infamous Assassins.

Iran's colorful terraces are a rare geological masterpiece.

Avenue of trees planted by cosmonauts before their space departures.

Mysterious spherical rocks in the semi-desert of western Kazakhstan.

One of the most horrible legacies of the Cold War is a site where the Soviet Union tested nuclear bombs on civilians.

Nicknamed Kazakhstan's Grand Canyon, this natural wonder lies east of Almaty near the Chinese border.

A modern tower, symbolizing the legend of a golden egg on top of the tree of life.

An abandoned Soviet-era park that, when viewed from the air, looks like a pentagram.

The remains of a monument in the remote Kazakhstani desert dedicated to the only men to die in outer space, the crew of the Soyuz 11 rocket.

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

The lovely lake that was naturally dammed, then naturally destroyed, then unnaturally saved.

Granny Smiths and Fujis can both be traced back to Kazakhstan, where apples still grow wild.

World's oldest and largest space launch facility, once a secret missile testing site.

Rusting ships sit in a desert where a sea used to be.

Hidden treasures belonging to Mongolia's most revered and multi-talented monk spent decades buried in the Gobi desert.