Indianapolis anchors the 29th largest economic region in the U.S., based primarily on the industries of trade, transportation, and utilities; professional and business services; education and health services; government; leisure and hospitality; and manufacturing.[20] The city has notable niche markets in amateur sports and auto racing.[21][22] The city is home to three Fortune 500 companies, two major league sports clubs (Colts and Pacers), five university campuses, and several museums, including the world's largest children's museum.[23][24] However, the city is perhaps best known for annually hosting the world's largest single-day sporting event, the Indianapolis 500.[25][26] Among the city's historic sites and districts, Indianapolis is home to the largest collection of monuments dedicated to veterans and war casualties in the U.S. outside of Washington, D.C.[27][28]