Tucked inside a 17th-century canal house on Oudezijds Voorburgwal, Our Lord in the Attic is one of Amsterdam's most quietly remarkable survivors. When the city turned Protestant in 1578, Catholicism became officially illegal. In practice, though, the authorities looked the other way, provided Catholics were discreet. Jan Hartman, a Catholic merchant, took this loophole seriously in 1661 when he converted the top three floors of his home into a fully functioning church, complete with a large organ. On Sundays, around 200 worshippers would file in off the street. Discreet it was not.

The church was made redundant in 1799 when Catholic emancipation meant proper churches could be built again, and it became a museum in the 1880s. VoiceMap's self-guided audio tours use Our Lord in the Attic to explain gedogen, the Dutch idea of tolerance within the law that made the city's famously liberal culture possible, connecting this canal house to Amsterdam's broader history of pragmatic openness.