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

A daily replay of the experiment that proved the rotation of the Earth.

North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A layered tribute to the work of mosaicist Isaiah Zagar.

An unusual, super-sized grocery adventure awaits in an Ohio suburb.

A circle of giant painted vases in the former pottery capital of the United States.

A favorite of Amelia Earhart, ranking among those rare bridges that can be crossed without changing sides of the river.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

The final resting place of the living embodiment of the famous Forest Service symbol.

A bronze statue on a downtown corner honors Minneapolis's favorite career gal.

This unusual lava tube spouts seawater during high surf.

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

A tribute to the life and work of the beloved "Peanuts" cartoonist.

The unbelievably opulent home built for an infamous newspaperman.

This engineering marvel is the longest bridge in Canada and one of the longest spans in the world.

Quite simply the largest tree in the world (by volume).

A collection of 20th-century automata, penny arcade games, and musical contraptions.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

These ancient sacred grounds granted amnesty to those who managed to reach them.

Get up close and personal with these majestic fish.

This industrial area was the dumping ground for massive amounts of trash, some of which washes up as tiny bits of sea glass.