<P> The route has markers at one mile intervals . Although the race publicity (athlete advice, timing charts and so on) is mile - oriented, the individual timing splits that are available to competitors after the event are kilometre - oriented . </P> <P> The course begins at three separate points: the' red start' in southern Greenwich Park on Charlton Way, the' green start' in St John's Park, and the' blue start' on Shooter's Hill Road . From these points around Blackheath at 35 m (115 ft) above sea level, south of the River Thames, the route heads east through Charlton . The three courses converge after 4.5 km (2.8 miles) in Woolwich, close to the Royal Artillery Barracks . </P> <P> As the runners reach the 10 km mark (6.2 - mile), they pass by the Old Royal Naval College and head towards Cutty Sark drydocked in Greenwich . Heading next into Deptford and Surrey Quays / Rotherhithe in the Docklands, and out towards Bermondsey, competitors race along Jamaica Road before reaching the half - way point as they cross Tower Bridge . Running east again along The Highway through Wapping, competitors head up towards Limehouse and into Mudchute in the Isle of Dogs via Westferry Road, before heading into Canary Wharf . </P> <P> As the route leads away from Canary Wharf into Poplar, competitors run west down Poplar High Street back towards Limehouse and on through Commercial Road . They then move back onto The Highway, onto Lower and Upper Thames Streets . Heading into the final leg of the race, competitors pass The Tower of London on Tower Hill . In the penultimate mile along The Embankment, the London Eye comes into view, before the athletes turn right into Birdcage Walk to complete the final 352 m (385 yards), catching the sights of Big Ben and Buckingham Palace, and finishing in The Mall alongside St. James's Palace . This final section of the route formed part of the 2012 Olympic Marathon Course . </P>

Over which bridge is the london marathon run