Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

This classic red schoolhouse is said to have been where Mary and her little lamb went to school.

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

This peaceful Massachusetts graveyard was one of the first "garden-style" cemeteries in America.

Impossibly life-like natural history models created out of glass by a father and son.

Three prestigious academic collections come together to create a world-class natural history museum.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

Portlandia is the second-largest copper repoussé statue in the United States.

This public art piece proves that in Portland even reporting the weather is a thing of whimsy.

This sandstone mansion was the home of two of Oregon's most important pioneers.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

Home of Howard Hughes' Spruce Goose.

The magic's in the hole!

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

A steampunk wonderland that preserves America's history of industrial innovation.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

America's "second most important bell" is a contentious spoil of the Civil War.

This bridge was the birthplace of a unit of measurement based on a fraternity joke.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

This impressive Boston holy house is the American mecca for Christian scientists.