This fantastical waterfall is hidden in a cave located in a cracked cliff.

An essential stop before plundering, BYO Cutlass.

San Francisco's newly reopened hands-on science museum.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

Rummage through this sunken ship, but leave your scuba gear at home.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A semi-scholarly approach to sex.

From scholastic to sepulchral - now under reconstruction.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

Haven for steampunks.

A discreet little stairway on St. Nicholas Avenue leads to a quaint and unexpected cobblestone street of 19th century wooden rowhouses.

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

The former estate of the Guggenheims, part of the opulent Gold Coast that inspired the Great Gatsby.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."

The Vatican of the movie industry turned into an actual church.

The loneliest island in New York.

Crumbling remnant of Rio's colonial past tucked behind Corcovado mountain in the neighborhood of Cosme Velho.

This stunning Brazilian library contains the largest collection of Portuguese texts outside of Portugal itself.

Beautiful public park off the beaten path and away from tourists.

A valley of unique erosion patterns lends to a view like nothing on Earth.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

A record-breaking pool that uses computers to turn ocean water into cleaner, private swimming water.

A glacier pocked with ice caves and surrounded by rainforests.