Nicholaston Burrows is a area of sand dunes backed by woodland about one and a half miles north east of Oxwich. It is not so easy to get to as Whitford Sands. There are two free parking areas: one, the nearest, at N51.5756° W4.1279° and the other, on the opposite side of the road, at N51.5761° W4.1271°. From the first area, take the footpath that runs along the side of and then behind the row of houses and then bear left to walk down across fields and through woodland to the dunes, where you should be able to find yourself a quiet spot.
Another way is to park at Oxwich Beach - expensive - at N51.5578° W4.1636° and walk along the beach to the left until crossing Nicholaston Pill, a walk of just over a mile. There is a bridge over the pill, but the waters spread out so far across the sands that it is easy to stay on the beach. The dunes are then ahead of you to the left.
This is a popular holiday area, so discretion will be needed.