Nominally a 7+ mile road race from the "Bay" to "Breakers" exudes San Francisco spirit in concentrated form - outrageous costumes mixed with a well-poured party with nearly a hundred thousand participants - bands, costumes galore, floats, lots of drinking and overall merriment in a unique and thrilling "anything goes" atmosphere.
The Downtown start is immensely crowded (definitely take Muni or BART!) and remains fairly packed until reaching the Golden Gate Park, where the combination of time and space thins the crowd down a bit.
There is also increasing chatter amongst higher-ups about cutting down on the partying - and every year there are some that seriously hurt themselves - enjoy yourself and be safe!
2011 was the 100th anniversary of the race, and it was another great one - don't miss the 3rd Sunday in May :)
Website: http://www.baytobreakers.com/
Wikipedia: http://en.wikipedia.org/wiki/Bay_to_breakers
