The oldest permanent circuit in Sweden, Karlskoga was Ronnie Peterson's home circuit. Built on land adjacent to a quarry, it is a flat succession of straights and hairpins that provides good viewing. It held a non-championship Formula 1 race for three years during the early 1960s and was twice included on the European Formula 2 calendar a decade later. The 1970 Kanonloppet was marred by an accident in which five spectators were killed, forcing the circuit to close for two years.