This ferry carries passengers across the Rhine propelled by no engine or paddles but by the river's current.

Study the Alien etchings in this fountain while you refill your water bottle.

This scenic spot is known as the birthplace of Switzerland.

A monument to peace, built by one man over the course of 25 years.

The most impressive of Basel's three remaining city gates.

This massive boulder was hurled into a Zurich church when a gunpowder depot was struck by lightning in 1652.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

The Great Fire of London and the regulation of one-way streets both started in this alley.

At almost 1,000 years old, this is the oldest known door in all of Britain.

The bridge is a secret gallery of discarded gum that has been transformed into miniature masterpieces.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

These ornate arches show how the course of the River Thames has changed.

An architectural oddity hides in plain sight on this iconic London bridge.

This one has sailed five times as far as Sir Francis Drake's famous ship.

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

The ritual has been performed uninterrupted for nearly 700 years.

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

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

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

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.