Quick: What do lavish costumes, naked people, 12 kilometers, and 80,000 people have in common? They're all a part of the longest-running footrace in the world, the Bay to Breakers. If you live in the Bay Area and don't know about this event, you need to brush up on your San Francisco history, because this is easily the biggest event of the year for our fair city.

Started in 1912 as a way to lift the city's spirits after the 1906 earthquake, the Bay to Breakers has become a San Francisco establishment, even breaking the Guinness World Record for the highest participation in a footrace. The name of the race is derived from the 96-year old course: the race runs from the northeast end of the downtown area near the Embarcadero (the bay side of the city) to the ocean breakers of Ocean Beach on the west side of the city. The race is 12K (7.46 miles) and attracts 80,000 people each year.

But this isn't your mama's ordinary 12K. Tens of thousands of participants prepare for this "race" by making floats, dressing up in extremely detailed costumes or dressing down and running the race buck naked. At the end of the race, numerous musical acts play at "Footstock," which is a free concert to everyone in the city. Needless to say, it is quite the spectacle, and while one can certainly participate as a legitimate runner, don't be surprised if you're bobbing and weaving through naked conga lines and full-service bars on floats.

This year, the race will be held on May 18. The registration fee is $44 before March 31, and $48 between April 1 and May 14, when the registration ends. To register, check out the Bay to Breakers website.