A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

An eatery within the Minneapolis American Indian Center writes colonial ingredients out of the story of Native American cuisine.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

The first memorial dedicated solely to the Black troops who fought for the Union.

This unassuming North Austin neighborhood was built to test the novel idea of home air conditioning.

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

The famous facade of Grand Central Terminal hides a regulation tennis court, and it's not the first one.

One man's extraordinary topiary garden in a small South Carolina town.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

This one-woman cemetery was a small civil rights victory.

The wooden house where the jazz great learned to play the piano.

The legacies of two historic Black American institutions live on in this unassuming brick building.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A six-story treehouse offers spectacular views of New York's Finger Lakes region.

Suspended above the ground in a thicket of towering Georgia trees is a modern architectural wonder.

A chance to sleep among the firs and pines of the Oregon forest.

A true treehouse near Hawai'i Volcanoes National Park.

Treehouse motel and treehouse-building school.

A whimsical village of unique treehouses resides in a Washington forest.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

One man's homage to the sun continues to grow like a glass fractal.