A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

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

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

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

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