The Lilac Bloomsday Run, held in the spring on the first Sunday of May, is a race for competitive runners as well as walkers that attracts international competition. Also in May is the Lilac Festival which honors the military, celebrates youth, and showcases the region. Spokane's nickname, the "Lilac City", refers to a flowering shrub that has flourished since its introduction to the area in the early 20th century. In June the city hosts Spokane Hoopfest, a 3-on-3 basketball tournament, among the largest of its kind. One of Spokane's most popular local events is Pig Out in the Park, an annual six-day food and entertainment festival where attendees may eat a variety of foods and listen to free live music concerts featuring local, regional, and national recording artists in Riverfront Park.