High Quality Content by WIKIPEDIA articles! The 1st World Scout Jamboree was held from July 30, 1920 to August 8, 1920 and was hosted by the United Kingdom at Kensington Olympia in London. 8,000 Scouts from 34 nations attended the event, which was hosted in a glass-roofed building covering an area of 6 acres (24,000 m2).