public penises in Prague, but if you want to see real, live naked men, head for Japan.
When I was in Osaka in 1986, I noticed that there were many more opportunities to see the nude male body than in the U.S. or Europe. Men hung around naked at home, among friends, at the medicinal hot springs (onsen), in non-gay bath houses.
And there are many naked festivals, hadaka matsuri, in which hundreds of men wear nothing but fundoshis (ceremonial loincloths) that display the backside.
Displaying the penis is frowned upon (photo by Nicholas Amheiser), but baskets and pubic hair are fine.
Usually the festivals are held in the summer, but the most famous, called Saidai-ji Eyo Hadaka Matsuri, is held in February in Okayama, about an hour by bus from Osaka.
They are struggling over possession of two wooden sticks (ofuda), tokens of good luck for the coming year, that are thrown out of a window at midnight by a Shinto priest.
The day before the festival, there's another hadaka matsuri with elementary school boys in fundoshis competing over rice cakes.
While you're in Okayama, you should also visit Okayama Castle and the Yumeji Art Museum.
See also the Penis Festival of Kawasaki, Japan, and the semi-nude British tradition, the Boxing Day Dip.