The movie, "I was a Male Warbride," starring Cary Grant and Ann Sheridan was filmed in Heidelberg in 1948. In the opening the market place next to the Holy Ghost church is shown and also city hall (Rathaus). You can go inside the Rathaus and see where civil marriage ceremonies are conducted. In Germany you have to have a civil ceremony, religious ones are optional although many couples do get married in church but receptions are smaller and more low key than in the United States.