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

Where royalty waits in the height of luxury.

A floating cat sanctuary on an Amsterdam canal.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

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

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

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This unusual elevator doesn’t stop or slow down.

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

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

A collection of biblical memorabilia.

Cat art as far as the eye can see.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

Amsterdam's former hotspot for public executions and dissections.

A beautifully eclectic mix of architectural styles.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Europe's official "zero-level," the equator of elevation.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The former headquarters of history's oldest megacorporation.

This “living museum” at UCLA exhibits thousands of plant species from all over the world.

A quirky collection of figurines backdropped by city views is hidden next to a popular restaurant in the Hollywood hills.