Old Moaner Travel
I haven’t been everywhere, but it’s on my list
London Getting Around: Overground
London Overground is a conglomeration of old local railway lines, linked to effectively form an outer circle providing a suburban service around Central London, with various “spurs” going to Watford, Enfield, Cheshunt, Chingford, Barking, Stratford, West Croydon and Richmond.

With 112 stations, covering 103.8 miles (167 km) it carries 184 million passengers a year.
A relative newcomer to the Transport For London (TFL) stable, they only took over the running in 2007, where several separate lines were amalgamated to form the new network.
On the network map the Overground system is shown in Orange.
To be honest the line isn’t ideal for getting to Central London but for moving around the outer edges of the centre it is ideal.
Most of the trains on the Overground network are of the new open plan style, they are very popular commuter lines.