This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

Cat art as far as the eye can see.

A floating cat sanctuary on an Amsterdam canal.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

This charming, hidden guild museum holds some 700 years of crossbow history.

Belgium’s famous peeing statue has worn many hats (and coats, and pants), which are on display at this small museum.

A huge old mansion full of thousands of toys, each there to be used and played with.

Meet the bronze beloved pet to a family of famous peeing statues.

Theme park featuring miniature replicas of European monuments.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Climb inside an iron crystal magnified 165 billion times its normal size.

This wondrous hideaway is suspended in a bamboo forest above a sanctuary for rescued llamas and alpacas.

The largest puppetry museum in the United States houses the world's most complete collection of Jim Henson artifacts.

This papier-mâché diorama celebrates an unusual landmark: the brightly-colored runoff from a local sock factory.

The country music legend's grave is surrounded by Astroturf because fans kept plucking out the grass.

One of almost 200 confirmed impact craters in the entire world, untouched for tens of millions of years.

This small cemetery contains the graves of prisoners of war who were interred at Fort McClellan during World War II.

Since it formed millions of years ago, this cave system has been a sacred burial ground, a Prohibition-era speakeasy, and the center of an amusement park.

A regular looking rock with an unbelievable history.

The Cimetière des Chiens et Autres Animaux Domestiques is one of the oldest pet cemeteries in the world.

This bunker in northern France was built by Nazi German forces with the intention of launching up to 50 V2 rockets at London each day.