A masterpiece in Golden Gate Park by virtue of the artist’s debt.

A priceless collection of the Nation's cryptologic history.

Smallest house in Toronto sits on a lot meant to be just wide enough for cars to drive through.

Iconic pyramid from famed British architect Norman Foster designed to represent all of the world's religious faiths.

Longest canal tunnel in the world, abandoned in the 1960s.

This Communist-era residential block is one of the longest residential building in Europe.

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

City Council meetings still happen in this historic building, impeccably preserved on the inside.

A bloodstain from "the wound of the transverberation of the heart."

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

A storybook European village in Berkeley.

Memorial built in 1922 in remembrance of WWI casualties.

Hindu temple of the dead home to hundreds of long-tailed macaques.

Copenhagen's celebrated theme park and gardens.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

If you were standing here on October 5th, 1950, you'd be dead.

Art in the form of a winding, man made crack in stone.

A famous alternative culture epicenter and where Joplin serenaded young hippies.

A hand-built folk art installation covered with messages of God's love.

Series of storm drains connected to a dark urban legend.

Giant Redwood-themed cafeteria operates under the golden rule, "Dine Free Unless Delighted."

Constructed in the 1920s, this former pencil factory is now an office building.

A 9-story, poured concrete structure which was used as a glue factory with an indelible smell.

Queen Anne style apartment house built in 1886.