Harvard National Model United Nations or HNMUN is the longest running college-level Model United Nations simulation in the world and among the largest in the United States. HNMUN is an annual four-day event held in February, composed of three thousand university students of which half tend to be international students. The conference is held exclusively at the prestigious Boston Park Plaza Hotel in downtown Boston. HNMUN was first run in 1955, ten years after the formation of the United Nations.