Which London Underground line is circular?

Which London Underground line is circular? The Circle line is London Underground’s circular line.

The line traces a loop around central London, linking many of the capital’s major railway termini and serving landmarks such as Westminster, Tower Hill, Baker Street and King’s Cross St Pancras. It is shown in yellow on the Tube map and has 36 stations. Although it is commonly called circular, its present route is technically a spiral rather than a completely closed loop.

The route developed from infrastructure opened in stages between 1863 and 1884. The Metropolitan Railway and Metropolitan District Railway gradually built the “Inner Circle,” joining railway stations around central London. Their rivalry delayed completion, but through services around the circle began in 1884. The Circle line first appeared as a distinct line on the Tube map in 1949.

A major change came in December 2009, when the line was extended west from Edgware Road to Hammersmith. Trains now generally complete the central loop and terminate at Edgware Road instead of endlessly circling. The line also shares much of its track with the District, Metropolitan and Hammersmith & City lines.