The 3rd World Scout Jamboree was held in 1929 at Arrowe Park in Upton, near Birkenhead, Wirral, United Kingdom. As it was commemorating the 21st birthday of Scouting for Boys and the Scouting movement, it is also known as the Coming of Age Jamboree. With about 30,000 Scouts and over 300,000 visitors attending, this jamboree was the largest jamboree so far.

Upton is a village in the northern part of the Wirral Peninsula, England, and is situated within 4 miles (6.4 km) of Birkenhead, 4 miles (6.4 km) of the Dee Estuary, a similar distance from the River Mersey, and 2 miles (3.2 km) from Liverpool Bay. The village is a ward of the Metropolitan Borough of Wirral in the metropolitan county of Merseyside. Upton was in the traditional county of Cheshire. At the 2011 census, the population was 16,130.