A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The world's oldest bookshop still in operation.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

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

A museum dedicated to the alleged Roswell Incident.

Strange physical sensations and optical contradictions keep visitors coming back for more.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

Former self-sufficient mental institution now a planned community.

Turnip-shaped island just off the Michigan shore in Lake Huron.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

The king of U.S. high points towers over every other peak on the continent.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

Gargoyle head that brings good luck.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

A tiny church on a man-made island in the Adriatic.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

A curious cave church carved into the face of a cliff.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

Three columns of volcanic rock shoot out of the ocean.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.