WWE SummerSlam is a professional wrestling pay-per-view (PPV) event, produced annually in August by professional wrestling promotion WWE. Dubbed as “The Biggest Party of the Summer”, it is one of the original “Big Four” pay-per-view events of WWE (along with WrestleMania, Royal Rumble, and Survivor Series).

The inaugural SummerSlam took place on August 29, 1988 at Madison Square Garden in New York City and was broadcast via pay-per-view. SummerSlam has been touted by WWE as their second biggest event of the year after WrestleMania. From 2009 to 2014, SummerSlam was held at the Staples Center in Los Angeles.

Since 2015, the event has taken place at the Barclays Center in the New York City borough of Brooklyn.

Source: Wikipedia