The Chincoteague Pony Swim is an annual event held on the last Wednesday of July in Chincoteague, Virginia. This unique tradition involves the swimming of the wild Chincoteague ponies from Assateague Island to the mainland. The swim is part of a larger celebration that includes a carnival and various activities for visitors. The event began in the early 20th century and is linked to the local practice of rounding up the ponies for sale. The swim attracts thousands of spectators each year, who come to witness the ponies' journey across the water and to support the local community.