Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

The attic of a four-century-old canal house hides a clandestine church.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

A collection of biblical memorabilia.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A beautifully eclectic mix of architectural styles.

Cat art as far as the eye can see.

Debatably clever, or just plain honest hotel advertised as "The Worst Hotel in the World."

The history and future of cannabis.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

Elaborate tile work in this railway station tells the story of Portugal.

This stunning Brazilian library contains the largest collection of Portuguese texts outside of Portugal itself.

A 125-meter long "tribute to the Brazilian people."

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

An alien church provides much needed silence in the midst of a Finland shopping center.

Architecturally stunning library serves as the hub of Finnish scholarly life and culture.

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

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

2300-year-old Roman road connecting the empire.

This subterranean necropolis holds three floors of antler-dug grave caves.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

Breathtaking and huge 430 year old maps of Italy.