Tiki luxury on Nob Hill.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A curious building honoring past and current members of a historic musical comedy troupe.

The oldest of only three existing statues of the great novelist stands in a city he did not care for.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

This forgotten building was one of the few Philadelphia-area breweries to survive Prohibition.

An Irish Memorial commemorating those who perished due to potato blight.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

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

This elaborate towering structure was once famed for its revolutionary height.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

Yo, Adrian!

The first American department store, and home to the largest operating musical instrument in the world.

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

Huge masonic hall in Philadelphia with lavishly themed rooms.

World's first "penitentiary," meant to be humane, drove men insane.

A piece of the iconic wall found an unlikely new home in a Vegas bathroom.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

A memorial to the victims of Argentina's "Dirty War."

This beautiful fountain was sculpted by a female artist who was ahead of her time.

The narrowest house in Buenos Aires is less than 10 feet wide.