Natural history museum celebrating biodiversity with a parade of taxidermy animals.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

Perfume museum and library.

A former squatter's paradise outside Prague.

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

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.”

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

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

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

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A traditional U-Bahn station in Berlin gets a string of rather untraditional benches.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

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

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Scattered throughout London are ancient remnants of the city's former bounding wall.

The final resting place to 300 Victorian-era pets hides inside the city park.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

Dedicated to the unsung history of human waste.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.