Billsmoor Park and Grasslees Wood are situated towards the north of Northumberland, in the north-east of England, north of Elsdon and west-south-west of Rothbury. Billsmoor Park, formerly a deer park, lies on the valley sides of the Park Burn, a north-running stream set amidst a west-facing lower slope at the south of the Simonside Hills. The roughly square park, extending to about, falls from above sea level at the south-east & south-west, to the centrally located stream which falls from to through the site. The B6341 road forms an eastern boundary of the park. The much smaller Grasslees Wood, slightly north of the park and on the other side of the road, is a strip of woodland up to wide and occupying, and is orientated in a north-east - south-west direction at about. Both park and wood are listed as an increasingly uncommon examples of an alder and oak woodlands, their scarcity arising out of clearfelling and over-grazing which prevents new growth from being established.
Vegetation
Wooded areas of Billsmoor Park support alder with some hazel on lower lying wet soils, and an undergrowth of soft rush, tufted hair grass, wood-sedge, greater-tussock sedge and pendulous sedge . Birch is found on steeper sections of the valley. Above the woodlands, open areas of the site support bracken and occasional birch, with grassland composed ofmat grass, sheep's fescue, sweet vernal grass and common bent. In very wet areas of the site, mire vegetation arises, including bog myrtle, broad-leaved cottongrass, grass-of-Parnassus and purple moor-grass and, around springs, yellow pimpernel , bugle and water mint . Grasslees Wood is dominated by sessile oak with some birch. Groundcover indicative of a dry acid soil includes sweet vernal grass, common bent, creeping soft-grass, wood sorrel, tormentil and bracken, together with remote sedge, oak fern and enchanter's nightshade. The condition of Grasslees Wood was judged to be favourable-recovering in 2013, with some concerns about deer grazing noted. Billsmoor Park was found to have an 'unfavourable-recovering' condition in the same year, with enclosures erected preventing deer grazing appearing to work well.
