Halkyn Castle, a castellated Victorian mansion (nprn 35865), is located in grounds on the immediate east side of Halkyn village, at the foot of Halkyn Mountain. The grounds are notable as the setting for the romantic, picturesque mansion designed by John Buckler for the Earl Grosvenor. The house is surrounded by gardens, the whole set in a small park (700123). 

The park was probably laid out in the 1820s-30s, the gardens established when the house was built in about 1824-27, with additional planting throughout the nineteenth and into the twentieth century. The gardens are laid out on ground sloping to the east around the house as a large area of informal woodland, a small area of formal terraced garden, one small ornamental walled garden, and no kitchen garden. The old church and churchyard of St Mary's was engulfed on the east side of the woodland, and the church was removed slightly later.

The ornamental woodland is laid out with winding rustic paths and stone steps, the house situated towards the southern end of the area which merges with the park woodland on the south. The mixed coniferous and deciduous woodland contains many ornamental trees. It is entered from the west drive at the north end of the garden. The drive winds through the woodland to the forecourt and around the east side merging with the east drive. Between the drive and the house is a raised gravel terrace surrounded by low stone walls, stone steps up to it. There is a similar terrace in front of the stable block. Below the terraces are sloping lawns, with a rectangular level area, formerly lawn tennis courts, cut into the slope at the south end.

From the south terrace a path flanked by yew topiary leads through ornamental shrubs in woodland to a small rectangular walled garden. Its long axis is north-west by south-east, with an apsidal south-east end, surrounded by walls about 1.5m-1.8m high. Inside, the garden is laid out formally, with lawns flanked by small rose beds and box edging. The southern end is taken up with an apsidal arbour of yew hedging.

Source:
Cadw 1995: Register of Parks and Gardens of Special Historic Interest in Wales, Clwyd, 120-2 (ref: PGW(C)68).