The NMR (available via the MAGIC web site) describes the site:
The monument includes a long barrow situated on a south east facing slope below the crest of a wide spur. The long barrow is orientated east-west but has been rounded by cultivation. The mound is 48m long and has a maximum width, at the centre, of 28m. It reaches a maximum height of 0.8m in the part that is no longer under cultivation but elsewhere survives as a slight rise approximately 0.3m high. Set into the east end of the mound is a large, lozenge shaped stone, known locally as the Hoar Stone. To the south of the centre of the mound is a large, kite shaped, capstone which covers a chamber. This was excavated in 1806 by Anthony Preston and is reported to have been divided into two segments and to have contained the remains of eight or nine skeletons. Although no longer visible on the surface, quarry ditches will flank either side of the mound and will survive as buried features 3m wide.
On her web site Celia Hadon recommends a visit during the Autumn or Winter when the field is not full of crops.