Tresilian house was constructed sometime shortly after 1800, when the London Builder, Thomas Morgan, took out a lease to construct buildings relevant to the production and exportation of lime in Tresilian Bay and built the present house. After his death shortly thereafter, the land passed to his widow, Mary Morgan who used the site as a hotel for sea-bathers, and from c.1810 to the middle of the century the building was used as a hotel, bathing house and public house under various owners. From the mid-nineteenth century, the building ceased to have these public functions with the drive to the house closed to the public by Dr John Whitlock Nicholl-Carne soon after moving to the house in this period. Nicholl-Carne also may have made enlargements to the house during his residency there. The current house is a two-storey construction faced in rough cast with an octagonal slate roof and a slated rear wing. There are a number of tall chimneys including a large prominent a central stack.

(Sources: GGAT Historic Environment Record, PRN 01776s; Brian James, `Notes and Queries: Tresilian?, Morgannwg: The Journal of Glamorgan History, XLV (2001), 139?41.)
A.N. Coward, RCAHMW, 26.02.2019