Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

360° views of the city plus five floors of optical illusions and hands-on science.

An Ecuadorian haberdashery that sets the record straight about the so-called "Panama" hat.

This 12-inch-tall wooden sculpture of a winged Virgin Mary has inspired much devotion and countless replicas.

The largest earthwork effigy in the world.

This demon atop the Notre-Dame de Paris looks utterly bored.

Claude Monet was baptized in this lavishly ornate Paris church.

The Argonaute submarine was the French navy's pride and joy in the 1950's.

The curious underground history of keeping Paris clean.

Abandoned railway line circling the city of Paris.

These caves secretly held national treasures during World War II.

An often overlooked ancient site in downtown Athens with substantial history (and nature).

A Byzantine-era church hidden in a wooded area below the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

How did an Australian statue of the Bard of Avon end up in the Hungarian capital?

One of the newest mosques in a city filled with thousands.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

The ancient latrines of the Greeks, in all their public glory.

The only residents of this abandoned housing development full of identical castles are stray cats and dogs.

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

This famous city eluded concrete detection until the early 2000's.