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

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

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

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

Monasteries on rock pillars, once accessible only by frayed ropes.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Eighty million natural history specimens call this gargantuan museum home.

This stately monument has been wearing a traffic cone hat for decades much to the delight of the locals.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

Anonymously sculpted and donated, these sculptures made from poetry books and pages are sprinkled around the city.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A 200-year-old collection of oddities and medical paraphernalia.

A scattered trail of street art adds a pop of color to the city's stark structures.

Sprawled across the Great Hall ceiling are various constellations and images relating to the zodiac.

The heads of two giant mythological water horses honor Scotland's horselord past.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

A beautiful Greco-Roman structure houses a well once believed to have healing powers.