This weekend Silverstone plays host to the Formula 1 British Grand Prix.  It's also (for the purposes of this post) 70 years old this year.  1948 saw the first post-war British Grand Prix and it was run at Silverstone in October 1948.  The previous year saw an informal race run there, but the official races there began in 1948.

Silverstone has seen much development to it's layout in its 70 years - and I've gone and recreated each one here for your enjoyment!!
1948

1949

1952

1975

 

1987

1991

1994

 

1996

 

1997

 

2010

 

 

2011

Buddh International Circuit

The Buddh International Circuit played host to the Indian Grand Prix

Sochi Autodrom, Russia

5 versions of the Sochi Autodrom for you here -
Analogue to fit 6.1m x 2.1m

Digital to fit 6.1m x 2.1m

Analogue to fit 10.7m x 3.4m

Digital to fit 10.7m x 3.4m

Analogue to fit 4.4m x 1.7m

Austin

The Formula 1 United States Grand Prix is at the Circuit of the Americas this weekend.

Queensland Raceway

Queensland Raceway, Australia

Mid-Ohio Sports Car Course

Mid-Ohio Sports Car Course, USA

Brazilian Grand Prix

 This weekend is the Formula One Brazilian Grand Prix at the Autodromo Jose Carlos Pace, Brazil

The track was originally known as Interlagos, and was much longer holding the event between 1972 and 1977

1978 and 1981 to 1989 saw Formula One move to the Autodromo Internacional Nelson Piquet, or Jacarepagua, in Rio, before it moved back to the shorter version of Interlagos