Wembley stadium's famous twin towers remain standing in the sunset, in west London ahead of their demolition which starts Friday. Wembley was built in 1923 as the country's national stadium. Ray Tidmarsh, from Dawlish near Exmouth in Devon will start the excavator after winning a radio competition. The west tower is due to be knocked down first and it is estimated the demolition of both structures could take around three days from the start on Friday. When completed the new Wembley will be the largest football stadium in the world with every seat under cover and no restricted views. The arch - with a span of 315 metres - will be the longest single span roof structure in the world.