The London Underground did give the East London line to the London Overground to ease its traffic.
Take the Underground (tube) to Victoria and then the Overground (main line) to Eastbourne.
It is in Rotherhithe, on the East London Line of the London Overground network. 51°29'36" N, 0°02'52" W
The Circle line connects with all TFL "underground" lines. It does not (directly) connect with the Emirate Air Line (the cable car link between Greenwich and the Docks) and the London Overground (an "outer" circle line around London). (Both of these are marked on the Underground Map, the latter [definitely] operated by TFL.)
Please bear in mind that this is an estimate (I'm a train driver for LUL). There are 11 lines, however the East London Line is closed and The Waterloo and City is a small line. These leaves 9 lines. Each line has a mean average of 75 trains per line some are more such as District and Central) which equals 675. The Waterloo and City own 15 trains (690), 20 engineering loco's (710), 20 in museums (730) and three steam loco's. Grand estimated total is 733.
45% of the overall network is underground. Nearly all of the lines run underground through the city centre and overground in the suburbs. The busiest stations tend to the be the ones which are completely underground. The Victoria Line is the only line which is completely underground (with the exception of the train depot at Northumberland Park). All the others run partly underground.
It is called the because of it's shape. If you look at the Paris Underground it is square but the London Underground has tube shaped tunnels and stations. Even the trains are tube shaped, apart from the lines which go overground for quite a way like the District and Circle line.
On the London Underground map, the Circle Line is coloured yellow.
The Jubilee Line.It connects into the lines at the following locations -Bakerloo - Baker StreetCentral - Bond Street, StratfordCircle - Baker Street, WestminsterDistrict - Westminster, West HamEast London - Canada WaterHammersmith & City - Baker Street, West HamMetropolitan - Wembley Park, Baker StreetNorthern - Waterloo, London BridgePiccadilly - Green ParkVictoria - Green ParkWaterloo & City - WaterlooOverground - StratfordDLR - Canning Town, StratfordThe other lines fail to interact with the following lines -Bakerloo - East London, DLRCentral - East LondonCircle - East London, Waterloo & City*, OvergroundDistrict - Metropolitan, Waterloo & City*East London - Bakerloo, Central, Circle, Metropolitan, Northern, Piccadilly, Victoria, Waterloo & CityHammersmith & City - Waterloo & CityMetropolitan - District, East London, Waterloo & City, Overground, DLRNorthern - East London, OvergroundPiccadilly - East London, Waterloo & City, Overground, DLRVictoria - East London, Waterloo & City, DLRWaterloo & City - Circle*, District*, East London, Hammersmith & City, Metropolitan, Waterloo & City, Victoria, Overground, DLR*Overground - Circle, East London, Metropolitan, Northern, Piccadilly, Waterloo & CityDLR - Bakerloo, Metropolitan, Northern, Piccadilly, Victoria, Waterloo & City**Some lines use Bank & Monument stations as an interchange. These are technically two different stations (although now connected) so it cannot be said that the lines are connected.
Central Line
East London Line was created in 1869.
The Circle Line Unfortunately this answer is wrong! According to Transport for London the only tube line to connect all London Underground lines is the Jubilee Line.
The Central Line of the London Underground runs West-East from Ruislip (16.5 miles west of central London) to Epping (20 miles North-East). The West-East branch of the District Line runs from Richmond (10 miles west of central London) to Upminster (20 miles East). The North-South branch runs from Edgeware Road (8 miles North) to Wimbledon (8.5 miles South).