Elevated freight railway turned wildly successful urban park.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

A beautiful geyser under environmental threat.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The world's brightest bioluminescent bay.

The world's second largest single-dish radio telescope, once used to contact E.T.

These curious caverns have been home to mushrooms, gangsters, and disco.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

When flour explodes, it's not a pretty sight.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

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

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

Stone monument honoring a town founder has a witch-boot shaped stain and a curse to go with it.

The biggest museum dedicated to insects in North America, one of the largest in the world.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Small ship votives hang from the vaulted ceiling of this port-side church with a Latin inscription on the wall.

Why have you never heard of the second most popular tourist site in New York?

The world's largest rotating world.

An 80-year-old house built out of newspapers.

An eccentric inventor's castle home with its own indoor weather system.

Solar powered Spectacle Island features all-green facilities.