Naked at Bay to Breakers - AMA
Bay to Breakers 12K is this Sunday, famous for its history (oldest continuously-run foot race in USA!), prestige (international elites contesting prize money!), costumes (people dressed as salmon running from finish-to-start, like swimming upstream to spawn!), party atmosphere (RIP drinking, floats, which were often rolling bars)...and nudity.
I've run it naked many times...AMA.