Hundreds strip down for Chicago's World Naked Bike Ride

CHICAGO, Illinois -- Hundreds of cyclists hit Chicago streets Saturday night with the wind in their hair - and everywhere else - for the 15th annual World Naked Bike Ride.

Organizers said the clothing-optional ride, which stretches about 14 miles throughout the city, celebrates "freedom from oil and the beauty of people."

The annual event has been held on the first Saturday in June since 2004. In past years, the Chicago Naked Ride has drawn more than 2,000 riders, according to its organizers.

Participants can also ride skateboards or wear inline skates - but they must use some form of "human-powered transport."

While clothes were not mandatory, helmets were encouraged.