All of Chicago's wood-paved streets are long gone but two alleys remain.

This historic hotel invented the chocolate brownie.

A hollow cement depiction of time's inexorable effect on the human body.

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

A gothic church spire sits atop this skyscraper, the tallest church in the world.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

An antiquated German apothecary on Chicago's North Side.

An unusual round church in London with a Templar past.

Historic funicular railway, believed to be the shortest railroad in the world.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A lush green oasis in the middle of Chicago.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

World-famous, Pink's still manages to keep its prized cult fetish status.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

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

The yawning maw of this pagan visage is said to bite off the hands of liars.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.