Circle line (London Underground) and the C Stock trains have recently been replaced by new seven-car S Stock trains, in a programme completed in 2015. In 1863 the Metropolitan Railway, the world's first underground railway, opened in London between Paddington and Farringdon, connecting the Great Western Railway's relatively remote terminus at Paddington with Euston and King's Cross stations and the City, London's financial heart. In the same year a select committee report recommended an 'inner circle' of railway lines connecting the London termini that had been built or under construction. In the next year the Metropolitan District Railway (commonly known as the District Railway)
London Underground Electronic ticketing in the form of the contactless Oyster card was introduced in 2003. London Underground services on the East London line ceased in 2007 so that it could be extended and converted to London Overground operation, and in December 2009 the Circle line changed from serving a closed loop around the centre of London to a spiral also serving Hammersmith. Since September 2014, passengers have been able to use contactless cards on the Tube. Their use has grown very quickly and now over a million contactless transactions are made on the Underground every day. The Underground serves 270 stations.