The site was begun on January 11, 1951. It covers an area of 1,350 square miles (3,500 km2) of desert and mountain lands. Nuclear testing at the Nevada Test Site began with a one-kiloton (4 terajoule) bomb. This was the same explosive force as a bomb using 1,000 metric tons of TNT. This bomb was dropped on Frenchman Flat on January 27, 1951. Many of the famous photos of the nuclear age were taken at the Nevada Test Site.