The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

A library of only unpublished manuscripts.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

This little town supplies Japan with most of its calligraphy brushes, still made by hand from animal fur.

A rapidly disappearing glacier filled with extinct grasshoppers, perfectly preserved in the ice.

The U.S. Air Force has an anti-satellite laser weapon.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

A painfully obvious spy house sits right across the street from the Russian Embassy.

The abandoned mine where American troops discovered a treasure trove of art and artifacts hidden by the Nazis.

A magical work of architecture where a wind turbine enables monks to levitate.

An enigmatic modern marker left next to a historic Roman site.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

The hollow trunk of this 650-year-old tree was used as a hideout by two Jewish brothers during World War II.

This lake in northwest Iran has started turning from green to red more frequently than scientists are comfortable with.

Neon signs that grace the windows of Bergdorf Goodman's and Tiffany & Co. come from this studio in Brooklyn.

A plaque commemorates the spot in the Oregon woods where the first-ever Geocache was hidden.

An institution dedicated to curiosity, logic, riddles, and Mongolia's long history of puzzles.

Underground vaults of a former brewery beneath Brooklyn's Crown Heights are now used to ripen cheese.

The whimsical construction on the roof has given rise to many a Montgomery myth about its contents.

An absolutely beautiful 200-foot stained glass installation traces the evolution of knowledge.

This cuddly rodent has a place of honor at a Russian institute for genetic research.

The laboratory where the Soviet secret police invented exotic poisons used to kill dissidents in hideous and (mostly) untraceable ways.

An abandoned jewel of a ballroom on the top floor of Australia’s busiest rail station echoes with the sounds of a bygone era.

More than 300,000 historical artifacts from the famous music venue, from Duke Ellington's handwritten score to The Beatles' booking slip.