The famous ones are naked festival Konomiya.

source http://tikitabi.com/tikipedia/event/detail/E20081202-T003/

Do you have other than pool and bathing naked in public?
In Japan, there are a lot of naked festival, but especially 

the famous ones are naked festival Konomiya.

 Usually, but it looks like

Shrine of the home page

http://www.konomiya.or.jp/

 source:http://omatully.com/matsuri/aichi/kounomiya-hadakamatsuri

When it comes to the festival of the day, naked man who was Minagi' of forces gather

 source: http://www.jalan.net/event/evt_180841/

Shinotoko(God man) Among the wait in the wings is a bunch of naked man, is the purpose be directed to the main shrine.
For this reason it has been devised so that you do not know appear from somewhere every year, also the people who put the water will have to naked man us for help Shinotoko(God man)

Still a lot of naked man will be very scuffle in order to touch this Shinotoko (God man)
In fact, naked men by touching to God man toward the main shrine.

 you are said to be bad luck to fall.

Konomiya naked festival is very intense festival, 

or would not say that seems to Japan festival.
Why not try to come join once.

It has been made every year around February.