This historical guided tour explores Sophiensæle as the former Craftsmen’s Association House and traces its changing roles over time: as a place of education and training for craftsmen (and women), as a site of organization for parts of the labor movement and part of Berlin’s urban history. At thetour’s center is the so-called Blutmai (Bloody May) of 1929, when workers’ demonstrations in Berlin were violently suppressed. In Neukölln, the city center, Friedrichshain and Wedding, thousands took to the streets; barricades were built at Hackescher Markt, Kösliner Straße and Hermannstraße. Police forces used firearms, resulting in numerous deaths. The tour highlights how places like Sophiensæle were embedded in these political struggles and examines their role in organizing, exchange and mobilization.