From the outside you would never know that this typical canal house hides an interesting secret and that’s exactly what its architect had in mind. For many years Catholics were prohibited from openly worshipping in Amsterdam and the solution for many was to hold services in secret. A wealthy German merchant named Jan Hartman bought the house you see now in 1661 and slowly began building a proper church with an altar, organ and seating for over 100 people in the attic. When the ban on Catholicism was lifted the building was immediately turned into a museum, which is why it has survived completely intact to this day. You can take a tour of the building and see how the family lived at the time and walk up the same wooden staircase that countless Catholics used to reach the beautiful church. Although it is currently being renovated and will include a visitors centre next door by 2013, the building is still open to the public.