This unassuming alcove in London’s famous Tower Bridge once served to capture, store, and display dead bodies from the River Thames.

The barrel-made lookout from Shackleton's final ship is tucked away in the crypt of one of London's oldest churches.

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

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

A mysterious carving from 17th-century London seemingly depicts a young boy sitting on a bread basket.

Hear the quietest sound from across the dome.

Floating pink tap installed for a flower show in London.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

Step back in time at this 19th-century kiosk.

Portugal's National Pantheon has a history of curses, collapses and financial problems.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

The dance of this huge clock is a magnificent and eerie commentary on good and evil in the history of humankind.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

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

The colorful stairs are made with marble from the world's major quarries.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The building where Mary, Queen of Scots was said to have bathed in white wine.

These steps offer a breathtaking view of one of Europe's most besieged fortresses.

Overlooking the burial ground is a tower designed to prevent thieves from snatching the recently deceased.