The unique hidden house church of Our Lord At the Attic where Catholic Amsterdammers gathered, prompts reflection on (religious) freedom. How free were Catholics in the 17th century when they were not allowed to express their faith in public? And how secret was the house church really? This guided tour takes you through the main rooms of the historic building. The museum guide talks about the history of the residents in the 17th century and the origins of the Catholic house church.