Portal tombs, sometimes called dolmens, typically consist of two upright portal stones flanking an entrance, a large capstone balanced overhead, and a backstone closing the chamber at the rear. What remains at Broomfields is a partial version of that arrangement, collapsed and tilted but still legible as the thing it once was.

The tomb sits on a very gentle south-west-facing slope, with its entrance oriented to the south-west, an alignment that may or may not be deliberate but gives the structure a particular quality of exposure. One portal stone remains upright, standing two metres high and 1.3 metres wide. Behind it, the gable-shaped backstone, 1.9 metres tall and 1.8 metres wide, closes the rear of a small chamber measuring roughly 1.9 by 1.4 metres. The other portal stone and the capstone, a substantial slab 3.5 metres long, 2.3 metres wide, and up to 1.6 metres thick, have both fallen forward. There is no surviving trace of a cairn, the mound of stones that would originally have covered or surrounded the burial chamber in many such monuments. Walshe noted the structure in 1931, and the dimensions recorded then give a clear sense of the scale involved: the capstone alone, despite its collapse, is a considerable piece of work for people without metal tools or wheeled transport.