ATLANTA — Atlanta's longest-running festival is entering its final day at a popular midtown park.Thousands are expected to attend the 80th annual Atlanta Dogwood Festival at Piedmont Park on Sunday. The three-day festival is regarded as the kick-off to spring and the third-oldest fine arts festival in the country.The event involves more than 260 fine arts, live music, a high school art exhibition, the Eco-Village, gourmet and festival fare, midway rides and games.