One of the largest and oldest caravansaries in Persia.

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

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.

The cathedral stands in New Jufa, Isfahan's Armenian quarter that was established in 1606.

One of the holiest Shi'i shrines in Iran honors the life and death of a learned noblewoman who became a saint.

This 17th-century structure is a beautiful testimony to traditional Persian architecture

Marked by the hand of the explorer Henry Morton Stanley.

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

A historic trade hub teeming with gorgeous architecture, colorful goods, and vibrant designs.

Named after a legendary garden called Eram in southern Arabia, built by order of Shaddad, an Arab king who wanted to compete with Paradise.

This circular Iranian jail was once a political prison run by the country's secret police.

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

A dreamy mausoleum honors Persia's most famous poet.

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

These little castles each held thousands of pigeons.

17th century mosque for Shah Abbas' harem.

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

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

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

After Christopher Columbus died, his son built a fancy house to rule from.

Built in 1512, the oldest cathedral in the Americas.

This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

Bronze footprints mark the path where a civil rights leader tried to march in peaceful protest before being knocked unconscious.

St. Augustine's record-setting narrow street was designed to protect against pirates.