Trevalyn Hall in Rossett, a Grade II listed building, is one of the most important Elizabethan houses in the country of Wrexham and was built by John Trevor in 1576.
The garden encompasses many tiers of historic development. Although there are no deer at Trevalyn, the deer parks remain, now as arable farmland. These are probably contemporary with the original house. Big Park and Pine Tree Park lie to the south-west of Trevalyn Hall and borders the picturesque village of Marford which was built in about 1813-14 by the Trevalyn Estate.
To the north-east of Pine Tree Park is Walnut Park. The orchard, now a field, lies to the north-west and south-west of the gardens. This still has an impressive earthen bank to keep the deer out. The kitchen garden is now only part walled on the north-west and north-east sides, but is thought to have originally been completely walled.
The Trevor family of Trevalyn were one of the leading families in East Denbighshire by about 1600 with numerous estates in both Flintshire and Denbighshire. The Plas Teg estate in Hope, Flintshire, was also acquired by the family when it was purchased by Sir John Trevor I (1563-1630) and it was he who built the present Plas Teg house in 1610.