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

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

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

The former headquarters of history's oldest megacorporation.

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

Amsterdam's former hotspot for public executions and dissections.

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

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

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

This cheese shop also houses a museum devoted to Dutch dairy.

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

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

This monument is dedicated to Balto, the heroic Alaskan sled dog.

Locals dubbed it the "Owl Building" because of its bird-like appearance.

A high-octane shrine to the greatest Texans who ever lived.

This simple frog painting created by musician Daniel Johnston embodies the spirit of Austin.

Designed by Horace Trumbauer in 1893, this Gothic-style castle is now a home for academics.

It appears as if a man is standing behind this giant airport clock, painting the hands in real time.

A solid steel plane designed to catch fire over and over again.

This monument is a stark reminder of the horrors of the Zanzibar slave trade.

This slowly crumbling mansion was home to one of East Africa's richest and most powerful slave traders.

Freddie Mercury's childhood home is now a monument to the iconic Queen rockstar.

In Zanzibar, a historic 19th-century palace is a reminder of the world's shortest war.

Mount Nyiragongo has erupted at least 34 times since 1882 and is home to the world's largest lava lake.