Different cultures treat the human body differently and different social norms.
However - a 15 second search found a group that seems to do this.
v While everyone is naked in an onsen, the body isn't necessarily exposed.
Yet, why are there Nudist Beaches in Japanese Anime, and most locations within Japanese anime always occur in Japan? I'm sure it may be found in an OVA or other 'adult content' - but I can't talk through experience.