Twins Days Festival in Twinsburg
Twins Days has gathered biological twins, triplets, and other multiples in Twinsburg, Ohio every summer since 1976, when the town marked the US Bicentennial with a festival tied to its own twin founders. Held the first full weekend of August at Glen Chamberlin Park, it now draws roughly 2,000 pairs of twins annually, plus researchers studying genetics, making it the largest twins gathering in the world.
Its globally unusual theme makes it one of Ohio's best weird/unique events.