What is 2003 summer sanitarium?

The 2003 Summer Sanitarium tour was a North American concert tour featuring headlining acts Metallica, Limp Bizkit, and Linkin Park, with supporting acts Deftones and Mudvayne. The tour ran from July 4, 2003, to August 24, 2003, and played in a total of 20 cities across the United States and Canada. It was one of the highest-grossing tours of 2003, with a total attendance of over 700,000 fans. The tour was named after a line in Metallica's song "Welcome Home (Sanitarium)" and was considered a major event in the metal and hard rock community.