On 15 December, London Underground’s Piccadilly line is 100 years old. London Underground (LU) said it had planned a series of events to mark the occasion of “one of the Tube’s most well-loved lines.”

The line opened on 15 December 1906. It originally consisted of 15.3km of twin tunnels running from Finsbury Park to Barons Court. A short section of surface track continued to Hammersmith and a branch to Aldwych opened in 1907.

Throughout the 1930s the line grew with extensions to South Harrow and Arnos Grove opening in 1932 and further extensions to Hounslow West, Uxbridge and Cockfosters opening in 1933. It was during this period that the iconic Art Deco stations designed by Charles Holden such as those at Arnos Grove, Southgate and Sudbury Town were built. Many of these are now listed buildings.

It has moved with the times and extended to Heathrow Airport; terminals 1,2 and 3, in 1977 and terminal 4 in 1986. The latest Piccadilly line extension, to Heathrow’s new Terminal 5, is due to open in May 2008. Currently the line is 72km long.