Ton-gwyn comprises a large house, now in ruins, with a complex of buildings to the north, also now in ruins. Ton-gwyn is denoted on the Ordnance Survey County Series mapping 1st edition (Glamorgan XL 3) from 1877 and the complex of buildings to the north appear in part on the 2nd edition and the full complex in 1919, on the 3rd edition.

Photographed during aerial reconnaissance by RCAHMW on 12th Nov 2008.
L. Osborne, 12th Feb 2012.