The first Newbury bypass was built in 1963; however, by the 1980s this in turn proved insufficient to cope with the huge volume of traffic travelling through the Newbury area. In 1981 a new road to be built to the west of Newbury, mainly following the path of the disused Didcot, Newbury and Southampton Railway railway line, was proposed to bypass the town centre. This route was very controversial because it ran through three Sites of Special Scientific Interest: Snelsmore Common plus the Rivers Lambourn and Kennet; Penn Wood which was part of the North Wessex Downs AONB (Area of Outstanding Natural Beauty); the English Heritage registered battlefield site of the first Battle of Newbury during the English Civil War in 1643; and The Chase, a National Trust nature reserve. It was also found that areas of the proposed bypass route were home to a rare snail, known as Desmoulin's whorl snail.