A small obelisk marks the spot where Captain Sam Greele was killed by a falling tree.

These ancient symbols freckling a Scottish cliff remained hidden for centuries.

A spiritual sanctuary in a natural cave.

A hands-on traveling collection of the innovative devices of yesteryear.

Visit the site of a subway powered by nothing more than air--and lots of it.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

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

Everyone from Mark Twain to Teddy Roosevelt has a pipe hanging from the walls of this historic chophouse.

An unassuming secret door once led to a legendary watering hole.

A Manhattan Episcopal church with an eerie underground crypt.

The highest point on the island known for buildings that touch the sky.

A quiet and contemplative oasis in the middle of New York's bustle and riot.

Hordes of precariously balanced stone figures crowd the shores of the Hudson River.

Little Red Lighthouse under the George Washington Bridge.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

Manhattan's deadly West Side railroad, which killed hundreds of New Yorkers, is remembered by this simple plaque.

A dilapidated dock tells the story of Titanic's missed arrival.

A whimsical monument deep in this park commemorates the groups that helped build it.

This derelict building used to house infirm Freemasons, their widows, and orphans.

Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

Mysterious rocks that ring musically when struck.