LOCATION, SETTING, LANDFORM, BOUNDARIES, AREA Hornby Castle is set on a high point in the rolling landscape of the Vale of Mowbray (the northern part of the Vale of York), and commands distant views to the North York Moors in the east and the Yorkshire Dales to the west. The small village of Hornby, clustered around the medieval church, lies below Hornby Castle on the western edge of the designed landscape. The park is set in a rural area of mixed farmland, much being arable. The land is very gently undulating, generally dropping away from the high point occupied by Hornby Castle. Boundaries to the park are not strongly defined, but this is thought to have been deliberate to make it appear more expansive by visually taking-in the surrounding countryside. Contributing to this design aspect is the use of the model farms of Arbour Hill, Home Farm and Street Farm as eye catchers. All three farms lie outside of the park with the first two lying to the south west of Hornby Castle, designed to be viewed from there and Street Farm being nearly 3.5km to the east, designed to be viewed from the approach to Hornby Castle from the Great North Road (the current A1), one of the designed rides extending out across the wider estate. The area of the park is around 240ha.
ENTRANCES AND APPROACHES The main approach to Hornby Castle in the medieval period is thought to have been from the west, from Richmond, with the tower of the parish church appearing on the skyline along with those of the castle, visually adding to the size of the castle. This approach is preserved as the modern road through Hornby village, with the grade II listed Hornby Lodge lying on the boundary between the park and the village.
The remodelling of the landscape in the C18 saw the lane to Hornby village from the west adopted as the principal approach, with two further C19 lodges: the first being Hackforth Lodge sited on the eastern boundary of the park, the second being Lawn Lodge controlling access from the lane to the garden front of Hornby Castle. All three lodges are early C19, built of sandstone ashlar with crenulated wall tops and hood-moulded openings, Hornby lodge being in the form of a two storey tower, the other two being single storey. The associated stone gate piers are ball-topped.
PRINCIPAL BUILDING Hornby Castle is grade I Listed, and although much reduced in 1930, retains the south east tower and southern range in use as a house. C15 in origin, the house was remodelled by John Carr in the 1760s who gave the building Classical proportions and regular, enlarged sash windows combined with gothic architectural detailing. The outer east and west walls of the original quadrangular castle also still stand, forming an enclosed courtyard to the rear of the surviving range. Service buildings to the north (including coach house, stables, laundry) have been converted into a number of separate domestic properties and are not included in the Registered area.
GARDENS AND PLEASURE GROUNDS Immediately around the southern side of Hornby Castle there is a terrace with formal lawns and beds with views across the countryside, with the string of ponds appearing as a meandering river in the middle distance with Arbour Hill Farm, framed by mature trees, forming an eye catcher beyond. The hillside below the formal terrace (beyond C19 iron estate fencing but enclosed by a ha-ha), is given over to meadow, studded with parkland trees.
Extending between the castle and the village down hill to the west, is the Rookery: an area of gardens including a number of mature yews and other trees likely to represent at least early C19 planting. These gardens are separated from the public road to the north and the village to the west by a high stone wall. At the foot of the hill there is the mill stream which is crossed by three simple bridges, the southernmost one clearly depicted on the 1806 plan at the northern end of Bowling Green Pond, with a path leading to the gothic summerhouse beyond the former bowling green occupying the level ground to the west of the pond. The summerhouse (the grade II Listed Museum) is ruinous, but had a raised ground floor room which was heated, with a basement below. It forms an alignment between Hornby Castle and Home Farm and retains the remains of a small, constructed pond on its south western side. To the north of the summerhouse there are the archaeological remains of the medieval moated site which included a high status stone building. In this area, overlying the moated site, archaeological remains of an early C17 formal garden have been identified, overlain by later landscaping. Archaeological remains of late 18th gravel paths have also been identified here and elsewhere within the pleasure grounds.
The summerhouse is also linked to Hornby Castle by a broad path that crosses Bowling Green Bridge. This grade II Listed bridge spans a cascade between Bowling Green Pond and Long Pond, and links to the western end of the ha-ha. A rustic bridge of five arches, it is built of tufa. Long Pond is formed by a long dam forming its south western side, along the top of which there is a path with a gateway into the parkland at the southern end. West of Long Pond is Springs Wood which was also part of the late C18 designed landscape, one surviving feature being a cascade, fed by Long Pond, which is crossed by a stone slab ford. This cascade and a smaller sluice feeds into Stone Pond which was largely silted in 2014. The dam at its southern end includes a brick lined tank interpreted as being for fish rearing, probably constructed in the C19. The next pond is Great Pond which is a serpentine C18 duck decoy pond which is mainly open water, although the decoy pipes are largely silted. On the northern bank at the eastern end is a partially ruined, twin chambered boat house. A second boat house, named on the 1857 map on the southern side of the pond, in not clearly identifiable. The southern side and eastern end of Long Pond are wooded to a similar extent as depicted in 1806, and two separate cascades issue from the pond, that at the east end retaining remains of a footbridge crossing the head of the cascade, with a later timber bridge crossing its foot. Great Pond formed the eastern end of the C18 designed landscape, however the stream continues to the early C19 New Decoy which is a four-armed duck decoy with a square pond which is still largely open water. This is set within New Decoy Plantation which forms part of the southern boundary of the eastern extension to the park.
PARK The park is largely pasture although also includes some land that is now arable. It retains a number of parkland trees and clumps and is bisected by the tree lined drive from Hackforth Lodge to Hornby. Parts of the park retains areas of surviving ridge and furrow and the northern half of the park retains a scatter of fish ponds. The park extends from the ha-ha to the south and east of Hornby Castle eastwards as far as North Road, the lane that leaves Hackforth village heading northwards. The watercourse with its chain of ponds forms the southern boundary. The northern boundary is marked by a road, extending eastwards to include New Covert Plantation (formerly West Close Plantation) which marks the north eastern corner of the park.
ADDITIONAL FEATURES Elements of the wider C18 and early C19 designed estate landscape extend beyond the Registered area. These include, on the northern edge of the park, the Grade II-listed Old Gas House (formerly the estate gas-works, now converted into a house); Icehouse Wood; kennels (unlisted); and the three model farms - Park House (now Arbour Hill), Hunter's Hill (now Home Farm) and High Street Farm (now Street Farm) - which form eyecatchers for the estate (all listed grade II). Elements of a network of extensive designed rides across the former Holderness's Hornby estate also lie outside the area Registered.
The extent and level of survival of the medieval deer park is currently poorly understood and so its western extent, which lies beyond the C18 pleasure gardens, is not included in the area Registered.
KITCHEN AND WALLED GARDENS To the north of the road through Hornby, marking the western end of the park, are the walled gardens (walls and attached structures are Grade II-listed) established between 1765 and 1806, and altered and enlarged in the second half of the C19. The inner kitchen garden contains a small late C20 housing estate. The walled gardens are excluded from the Registered area.