Other professional and semi-professional teams in Washington, D.C. include the DC Defenders of the XFL, Old Glory DC of Major League Rugby, the Washington Kastles of World TeamTennis, and the D.C. Divas of the Independent Women's Football League. The William H.G. FitzGerald Tennis Center in Rock Creek Park hosts the Washington Open, a joint men's ATP Tour 500- and women's WTA Tour 500-level tennis tournament, every summer in late July and early August. Washington, D.C. has two major annual marathon races, the Marine Corps Marathon, held every autumn, and the Rock 'n' Roll USA Marathon, held each spring. The Marine Corps Marathon began in 1976 and is sometimes called "The People's Marathon" because it is the largest marathon that does not offer prize money to participants.