This ancient fortress in Iran was once the oldest and largest treasury in the world.

The tower in this 1,000-year-old mud-brick village seems to vibrate for no apparent reason.

Long before air conditioning, Persian architects found an ingenious way to cool off.

This 12,000 year old Iranian cave village has been continuously inhabited for over 3,000 years.

The colorful soil of Iran’s "Rainbow Island" attracts artists and nature lovers.

This ancient burial site is believed to be one of the first earthquake-protected structures in the world.

A dreamy mausoleum honors Persia's most famous poet.

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

The fire inside this temple has burned for more than 1,500 years.

The hottest, driest, and most scenic desert on Earth.

These little castles each held thousands of pigeons.

17th century mosque for Shah Abbas' harem.

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

One of the world's largest salt caves is filled with fragile salt sculptures, salt rivers, and huge salt megadomes.

This vast, water-filled underground labyrinth can only be toured by boat.

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

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

Putrefaction plateaus in Iran, where the dead were sent for decontamination before going to their final resting place.

Ancient structures used to make and preserve ice in the deserts of Persia.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

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

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

A lush desert oasis in the shape of a narrow crescent.

Natives of this mud-brick desert village use an ancient irrigation system to grow sweet, seedless grapes.