Mayfest is an annual four-day community festival in Fort Worth, Texas that began in 1973,held on 33 acres of Trinity Park. The festival attracts about 200,000 people during the first weekend of May. Mayfest also includes the Mayfest Run that has USATF certified 10K, 5K and a 1K Fun Run winding through Trinity Park along the Trinity river. Mayfest has free admission for senior citizens on Thursday and for members of the armed forces on Sunday.