Two stone columns flank the grand Venice square, but there were supposed to be three.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Go inside to really appreciate this 500-year-old technological masterpiece.

This group of small islands on Lake Nicaragua formed after an eruption of the Mombacho volcano.

The youngest volcano in Central America.

A crumbling cathedral condemned by an earthquake.

Bridge that died in war and was resurected.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

An apparition of Virgin Mary in Herzegovina.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

An architect's childhood fantasy treehouse made real.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

A dead saint, a deadly poison, and a mysterious holy ooze.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

This expansive bridge in the Canadian wilderness was originally just built for friends.

Oldest building in California still in use.

California's largest steel arch bridge.

From Japan to Italy, this California park explores the world's cultures through their gardens.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.