I have the M4 motorway in my Port Talbot back garden

Narelle Cowan and Aimee Lipley's gardens have a few things in common. Both have pretty plants, chairs for al fresco dining - and one of the UK's busiest motorways. About 75,000 vehicles travel over the elevated concrete monolith hanging about 45ft (14m) above their plot every day on the main route between London and south Wales. "I call it my free gazebo," said Aimee. "I love it under here, when it's raining you can walk to the shops without getting your hair wet." The two-lane carriageway in the sky was one of the first sections of the M4 and a relic of the 1960s motorway building boom after the explosion in post-war car ownership. There are many examples of motorways built close to people's homes in the UK's biggest cities such as London, Birmingham and Glasgow but few are more stark than in Port Talbot where the M4 - which opened on 22 July 1966 - cuts the Welsh industrial town in half. "I've got three pillars of the M4 in my back garden, I use one to help hang my washing line up," said Narelle. "It's convenient because the motorway covers the back half of the garden so I've a dry area and it acts as my sunshade, which has been handy in recent weeks." The 34-year-old mum-of-one