A Grade I listed building, the castle is now in the care of Neath Port Talbot County Borough Council.

The Margam estate was occupied in the Iron Age, and the remains of a hill fort from that period, Mynydd-y-Castell, stands north of the castle.

William Henry Fox Talbot was a frequent visitor to Margam, and the castle featured as an image in some of his early photographic experiments.

[8] Margam's links with photography also include being the location of the earliest known Welsh photograph, a daguerreotype of the castle taken on 9 March 1841 by the Reverend Calvert Richard Jones.

[6] David Evans-Bevan, who bought it, found it too large to live in, but could not find any public organisation interested in taking it on, and it fell into disrepair.

[13] The design is highly asymmetrical with irregular gables, turrets, parapets, bay, lancet and oriel windows, groups of chimney stacks and a great deal of heraldic decoration.