Iranian tombstones shaped like male and female sexual organs.

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

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.

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

Hundreds of stones dangle from barren trees in the middle of the desert.

A dreamy mausoleum honors Persia's most famous poet.

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

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

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

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

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

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

Iran's colorful terraces are a rare geological masterpiece.

This little valley along Highway 1 is engulfed by thousands of lilies during the spring season.

This large pile of traveler-curated rocks by the dry lakebed is a longstanding tradition on the Old Mojave Road.

The largest dune field in the Mojave offers a chance of hearing the 'singing sands.'

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

Nearly 300,000 acres of wildlife, natural splendor, and a hidden ghost town have been designated a national monument.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Once a menacing challenge for trailblazers, this trail is now the most scenic drive in Utah.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Rippling sand dunes frozen in the Arizona rock.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.