Old Street Roundabout
Old Street Roundabout is a roundabout located on the boundary of the London Borough of Hackney and the London Borough of Islington in central London. It is an interchange system at the junction of Old Street and City Road. It is sometimes known as St. Agnes Well after the shopping centre beneath it, while the area surrounding the roundabout is often colloquially known as Silicon Roundabout, owing to the prominence of technology companies there. In 2019, major refurbishment work started to renovate the entire area to create a more pedestrian and cycle friendly environment, which will open in 2020.
City Road crosses the roundabout, running south towards the City of London and Moorgate and Liverpool Street stations, and north-west towards Angel, King's Cross, St. Pancras and Euston. The roundabout, the north-western part of City Road, and Great Eastern Street form the boundary of the London congestion charge zone (CCZ).
St. Agnes Well
The shopping complex in the underpass at the centre of the roundabout is named St. Agnes Well, after an ancient well thought to have been located about 200 metres to the east, at the junction of Old Street and Great Eastern Street. Remnants of the well can be found within Old Street station. 
Old Street station
Old Street station is located below Old Street Roundabout. It is served by the Bank branch of the London Underground Northern line and by National Rail Great Northern trains. With the increase in passenger numbers using the station, in 2014 Transport for London announced that it was to offer pop-up retail space at Old Street station as part of a drive to increase its revenue.
A number of cycling accidents have occurred at Old Street roundabout. According to the London Cycling Campaign, the junction is among the top three in London for accidents involving cyclists. Within a few days in February 2011 two cyclists were severely injured in collisions involving lorries on or very close to the roundabout. In another collision involving a lorry in 2008, a cyclist suffered severe leg injuries, which the police described as "potentially life-changing". In response to this Transport for London have proposed a massive transformation of the roundabout, into a pedestrian square with segregated cycle lanes and road signals. On the 25th July 2018, a cyclist was severely injured on Old Street roundabout following a collision with a lorry.
Following an extensive public consultation held in 2014/2015, plans to transform the roundabout began in 2018.. In 2019, major refurbishment work began by [Transport for London] (TfL) in conjunction with Morgan Sindall. and the Borough of Islington and the Borough of Hackney to renovate the entire roundabout complex, to create a more pedestrian and cycle friendly environment.. Traffic will be two-way to improve pedestrian crossings and allow segregated cycle lanes. The roundabout is being removed so as to create a new well lit pedestrianised public space around the new station entrance.
- "Morgan Sindall awarded £15 million Old Street Roundabout project by TfL". Transport Britain. 2017.
- London's Holy Wells Archived 9 November 2013 at the Wayback Machine
- Bradshaw, Tim (29 July 2008). "silicon-roundabout-is-this-the-heart-of-the-uks-new-dotcom-boom". Financial Times blog. Retrieved 10 July 2009.
- "Silicon Roundabout". The Economist. 27 November 2010. pp. 63–64.
- Prigg, Mark (30 July 2008). "Roundabout is London's Answer to Silicon Valley". Evening Standard. Retrieved 10 July 2009.
- Coleman, Jasmine (4 March 2011). "Safety concerns for cyclists on Old Street roundabout following crash". Hackney Gazette. Retrieved 25 March 2011.
- Coleman, Jasmine (24 February 2011). "Old Street crash: woman cyclist critically ill". Hackney Gazette. Retrieved 25 March 2011.
- Marshall, Tom (16 February 2011). "Cyclist injured in City Road crash". Islington Gazette. Retrieved 25 March 2011.
- "Old Street roundabout accident: "Life-changing injury"". Retrieved 25 March 2011.
- "Revealed: Radical plan to transform Old Street roundabout into pedestrianised square". Retrieved 24 February 2015.
- "Female cyclist, in her 30s, hit by lorry at busy roundabout in east London". Evening Standard. Retrieved 26 July 2018.
- "Have your say on transforming Old Street roundabout - Results Updated 2 Oct 2018". Transport for London. 2019.
- Matters, Transport for London | Every Journey (2019). "Old Street roundabout". Transport for London.