The only ancient site that remains on the south bank of the sacred Ilissos river.

A tiny Greek Orthodox church from the Ottoman era hides on a busy city street.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

The ritual has been performed uninterrupted for nearly 700 years.

William Blake claimed to have painted this gothic masterpiece after encountering this nightmarish being in a vision.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

This early version of the guillotine was used to execute the man responsible for its construction.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

Ship-sized kinetic sculptural fantasy.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

Two plaques commemorate the site of Shakespeare's first theatre.

A verdant 17th-century-style garden hidden along Edinburgh’s Royal Mile.

Archduke Ferdinand II's collection of rare objects is considered one of the oldest museums in the world.

Catacombs turned marketplace.

A fearsome dragon clings to a corner of Munich's city hall.

Hear the quietest sound from across the dome.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

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

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Inspired by Thomas Stothard's painting of the "Journey to Canterbury," albeit with Canterbury natives.

A set of medieval stained-glass windows tell the gruesome story of a Viking siege.

An impressive armored bronze effigy marks the tomb of one of the medieval era's greatest warriors.

Take a steam-powered ride straight out of the past on this Appalachian rail line.