The 17th century Dutch Reformation was a hard time for those who wished to remain Catholic in Amsterdam. Those who dissented from the Dutch Reform Church were forced to worship in hiding in a “out of sight, out of mind” manner tolerated by the city fathers. As a result, many of these “house churches” sprang up around Amsterdam.
The Museum Ons’ Lieve Heer op Solder was originally built in 1631 on the prestigious Oudezijds Voorburgwal.. It was built as a house for successful merchant, Jan Hartman. He owned the tall canal house and the two houses behind it. Hartman was Catholic, and his son was training for the priesthood, so he decided to convert the top three floors of his house into a secret Catholic church.
The self-tour starts on the first floor (second flour for U.S. folks) so you will begin by climbing the steep narrow stairs that are common in the tall 17th century Amsterdam homes.
The museum is currently under renovation, but you can walk through the rooms, which are being carefully restored to what would have been their original 17th century appearance and climb the narrow stairs to the unique Catholic Church in the attic.
The Canal Room (day room) was located in the front house and is where the residents would have spent their day. The room had no heating at that time and since it was at the front, the noise and the smell of the canal were a problem so wall curtains were used to add comfort and soundproofing to the room. The room is fitted with 17th-century furniture.
The Church of St. Nicholas was finally built in the 1880’s to serve the Catholic community ending the use of the "schuilkerk" and a few years later in 1888, the house church was opened as a museum. Today, it is one of the oldest museums in Amsterdam, second only to the Rijksmuseum.
Information for this article provided by DK Eyewitness Travel Amsterdam, Wikipedia,
and Museum Ons' Lieve Heer op Solder