Summerfest is an annual music festival held in downtown Milwaukee, Wisconsin. First held in 1968, Summerfest is located at Henry Maier Festival Park, adjacent to Lake Michigan and Milwaukee's central business district.

Summerfest attracts approximately 800,000 people each year, promoting itself as "The World's Largest Music Festival", a title certified by the Guinness World Records in 1999. 

During Summerfest, the 75-acre (30-hectare) park hosts performances over 11 days, from late June until early July (including the Fourth of July). The festival includes 12 stages with over 1000 performances.

The performers include local and nationally known music talent from various genres, performing throughout the grounds from noon to midnight, including the 23,000-capacity American Family Insurance Amphitheater. 

Summerfest also showcases a wide variety of food from many Milwaukee-area restaurants. Other Summerfest attractions include shopping vendors, fireworks (including "The Big Bang" on opening night), family activities, and more. Summerfest is operated by Milwaukee World Festival, Inc. a non-profit organization, which is governed by a volunteer board of directors.

According to en.wikipedia