The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

Behold the rickety wooden glory of the world's oldest operating roller coaster.

With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.

The Pennsylvania landscape depicted by a quarter mile of mosaics made from used road signs.

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

In which a local geological marvel becomes a quaint roadside attraction.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

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

This solo operation offers the world's only whey wines in flavors such as chocolate-orange.

The U.S. Navy's last diesel-electric submarine rests half-submerged in the middle of Portland.

The largest wooden building in the world now houses a fascinating collection of aircraft.

Home of Howard Hughes' Spruce Goose.

World's largest porcine hairball sits in a collection maintained by Benedictine monks.

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

A vertically floating hemlock controls the waves and weather at Crater Lake.

This massive mushroom has spent centuries eating its way across a huge swath of Oregon.

10,000 flowered plants bloom in the City of Roses.

Treehouse motel and treehouse-building school.

This charmingly homemade amusement park has been growing for 40 years.

On the Oregon coast there is a natural hole that seems to be draining the sea.

This large Sitka spruce that appears to be floating in mid-air, has defied logic for years.

Once a year, thousands of naked cyclists flood the streets of a Seattle neighborhood.