Here a few hot places in Switzerland:
Zurich, Magnusbar has a darkroom downstairs. Sunday and Wednesday evening is dresscode Naked or Undeerwear. 90% are naked. Most fucking there is bareback and everybody uses Poppers.
Schlieren near Zurich, Rage Club opens Thursday until Sunday. Has a huge dark area. You always find some horny guys who love it bareback.
Lausanne, Trafick Sex Club. Open every day, some themes nights, Sunday afternoon naked. The best is on every 1st Saturday of the month Naked Bastards. A lot of people, all naked, and many love bareback.