The oldest hall in Iceland was written of in the Sagas and features a centuries-old escape tunnel.

A hidden alley in urban Baltimore is a haven for graffiti artists.

Easter in Westminster may be the only time and place to behold Edgar Allen Poe made entirely of Marshmallow Peeps.

Ship skeletons haunt Baltimore's waterways.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

Remains of a historic fountain that was mysteriously lost in the demolition of a D.C. traffic circle.

An intricately designed junk art house with four extravagant junk art cars hidden in the suburbs.

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

Outsider art meets paleontology at this roadside reptile repository.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

One of the few remaining carousels built by master amusement park carver Charles I.D. Looff.

Along a California highway is a kind of Jurassic Park made of metal.

This Maryland farm is known for its amazing corn mazes and its 30-foot junkbots.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A tiny piece of the Moon is embedded in this stained glass masterpiece.