A small etching on the white marble parapet was written in runic script by a Viking mercenary.

1513 Turkish world map, full of European state secrets and snarky commentary.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

A marvel of Byzantine engineering under the streets of Istanbul.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Giant pagoda houses the car that drove Thích Quảng Đức to his death by self-immolation.

Meant to be a lavish presidential home, the palace became a symbol of the fall of South Vietnam.

Witnesses claim the Virgin Mary statue outside the church once mysteriously shed a single tear.

This French colonial post office is arguably the grandest in all of Southeast Asia.

Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.

The notorious "Hanoi Hilton" where Vietnamese colonial subjects and later American POWs, including John McCain, were imprisoned.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

Ha Long Bay's "Cave of Surprises" houses a popular phallic rock formation.

Home of the unusual art of water puppetry, one of Vietnam's oldest curiosities.

Standing atop 2nd-century Roman ruins, this church is one of the oldest and most iconic in Old Cairo.

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

The largest known Ancient Egyptian obelisk.

In Egypt's expanding metro area, many of the neighbors are dead.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

Ozymandias’ time-keeping temple.