Hadaka Matsuri
A Hadaka Matsuri is a type of naked festival that occurs in Japan.  It originates from Saidaiji Temple in Okayama.
The festivals take place all over Japan but the 'Saidai-ji Eyo Hadaka Matsuri' is the most popular with over 9000 men participating on average.
During this festival the men wear nothing but a loincloth as they attempt to seize sacred sticks which are thrown to them by priests from the temple.
This specific festival takes place at night on the third Saturday every February anually.
More information about the festival and how to get there is available at:

Hadaka Matsuri