The "Magic Roundabout" in Hemel Hempstead, Hertfordshire, England, is the familiar name given to the Plough roundabout. The familiar name comes from the children's television programme, and is also used for a similar junction in Swindon and the M40 junction in Denham. The official name relates to a former public house, called The Plough Inn, which was between the junction of what is now Selden Hill and St Albans Road. It has also been known as the Moor End Roundabout as it is adjacent to the part of Boxmoor nearest the town. Before Hemel Hempstead became a New Town the roads met in a simple junction which was then replaced by a standard roundabout.
Constructed in 1973, the "Magic Roundabout" in Hemel Hempstead was voted the UK's second-worst roundabout in a 2005 poll held by an insurance company (the winner being its Swindon counterpart).
In 2011 the roundabout was voted the best in Britain by motorists in a competition organised by a car leasing service.
The original magic roundabout had six exits in total, with the British Petroleum building spanning "Marlowes", the road leading to the town centre, in the approximate position of the earlier railway viaduct. The BP building was found to be unstable due to defective reinforced concrete and the exit had to be closed. The building was demolished but the original route was not restored, although a newer side exit from the roundabout replaced the junction with Marlowes off a side road.
Coordinates: 51°44′46″N 00°28′23″W / 51.74611°N 0.47306°W