The South Circular Road in south London, England, is a major road that runs from the Woolwich Ferry in the east to the Chiswick Flyover in the west via Eltham, Lee Green, Catford, Forest Hill, Dulwich, Tulse Hill, Streatham Hill, Clapham Common, Clapham Junction, Wandsworth, Putney, Barnes, Mortlake and Kew Bridge. Together with the North Circular Road and Woolwich Ferry, it makes a complete ring-road around Central London and is a former boundary of the Ultra Low Emission Zone. The South Circular is largely a sequence of urban streets joined together, requiring several at-grade turns, unlike the mostly purpose-made carriageways of the North Circular. As a result, it is frequently congested.