Although no extensive work was undertaken to the grounds, Pryce did begin some additions, including the construction of the walled garden, dipping pools and some ornamental plantings.

[4] In 1891 the Dyffryn Estate was sold to John Cory by the then owner, a banker named Henry Ellis Collins.

"[4][7] Dyffryn House and Gardens underwent restoration in 2006 with a £8 million grant,[4] £6.15 million from the Heritage Lottery Fund,[4] and the Grade II listed Edwardian gardens have been restored to the original design drawn up by Thomas Mawson in 1904 for the coal baron John Cory.

The National Trust took over stewardship of Dyffryn House and Gardens on a 50-year lease from the Vale of Glamorgan Council in January 2013.

[12] A long narrow mansion, the architectural style is vaguely Second French Empire[11] The main entrance, located on the north side of the building, is protected by a porte-cochere, which leads into a lofty hall.

The hall also features the most notable of the manor's impressive chimneypieces; incorporating at its centre a late 17th-century marble cartouche of arms flanked by life-size wooden Mannerist figures of Ceres and Prudence.

[11] In 2007, the Vale of Glamorgan Council appointed £1.4 million to repair and maintain Dyffryn House's walls and roof.

[14][13] At the southern end of the lawns is the Vine Walk, and Lavender Garden, the latter containing a red brick folly.

The Pompeiian gardens, entered via an archway dated 1909, were originally inspired by Reginald Cory's trips to Italy.

These include a life-size prone stone lion, a terracotta statue of a palm-bearing female, signed "E. Kuhse", (1881) of German origin[13] and to the rear of the house outside the visitor centre is a large bronze of a mandarin riding a bull.