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

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

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

Medieval torture techniques with a modern conscience.

Architectural monsters are devouring this palace's every door and window.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The underground sanctuary of a mysterious ancient cult.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

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.

The U.S. Navy's last diesel-electric submarine rests half-submerged in the middle of Portland.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

The awe-inspiring ship from the golden era of cruising has an incomparable history and a reputation as one of the world’s most haunted places.

Known as one of the most climbed mountains in the world, this barren peak is permanently bald thanks to an anti-wolf fire.

At just six feet two inches deep, it is said by Guiness and Ripley to be the world’s narrowest freestanding office building.

"Girl in a Wetsuit" is what happens when a sculptor has to find a way around a 100 year old copyright.

Traditional 15th century Chinese garden in the middle of Vancouver.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.