You can also show your dick in non-nude sections. You have to be sensible of time and place but the likelyhood of someone complaining is very low if you do it near a lake or the sea. Pretty high when you do it in the city center or in church.

At least it was common in the region I lived, there are more prissy places though. I wouldn't do it anymore when everyone has a smartphone though even if taking pictures will get you in huge trouble too.