The portrait of a man from Japan who sent weekly letters to a Dutch hotel he never visited.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

A unique collection of gilded age mechanical pianos.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

The last of Amsterdam's original sea level markers remaining in place.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

The spectacular history of spectacles on display.

An overgrown and largely forgotten cemetery lies hidden within the outskirts of Amsterdam.

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

Where royalty waits in the height of luxury.

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

This collection of 20th-century toys is filled with a lifelong personal toy collection brought from the U.S. to Amsterdam.

A collection of biblical memorabilia.

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

A line number in Amsterdam that will likely never be used again due to its tragic history.

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

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

This unattributed sculpture in Amsterdam is hiding in plain sight.

This plaque marks the former home of one of the first women physicians in the Netherlands.

The facade of this bank has changed little over the centuries, including its unique welcome sign.

A public urinal so pretty, it was declared a national monument.

Amsterdam's Red Light District leaves little to the imagination.

This vast collection of smoking pipes from across the world spans centuries.