Poor's Allotment and The Park are two sizeable, adjacent patches of acidic heathland, dominated by heathers, gorse and bracken, nearly 150 acres in area, either side of the B4228 four miles north of Chepstow, close to the east rim of the River Wye valley. The land became a nature reserve quite recently, having previously been managed by other organisations; the Park, west of the highway, by the Forestry Commission (considered to be part of the Forest of Dean), and Poor's Allotment, on the east side, by the Parish of Tidenham. This latter region is also a site of special scientific interest, because of its range of plants and the contrasting habitats, since as well as the heath, underlain by sandstone, part also contains calcareous vegetation, above Drybrook limestone. The Park is entirely heath.
Both sections are similar in appearance, and are crossed by various trails and tracks, running through a mix of grassland and bushier areas, with scattered trees. Poor's Allotment has the best views, across the Severn estuary to the east, but neither is particularly interesting scenically, and the plant life, while incorporating a few uncommon species, is generally less varied than for meadow-based nature reserves, in common with other heathland. About 3 miles of paths cross the reserve, and to explore all areas would take several hours.
The main access to the nature reserve is the Tidenham Chase car park, along the B4228. From here a wide track heads west through the middle of the Park to an alternative access point along Miss Grace's Lane. An intersection about half way is with a north-south path, which links with another route most of the way around the perimeter. Lesser trails enter other areas, while cross-country walking is possible in places. The Park contains several small ponds, towards the southeast, and a few patches of trees, in the centre and along the northern edges; the remainder is heath and scrub. Also towards the middle are a few shallow excavations from ancient quarries.
A path on opposite side of the road from the Tidenham Chase car park enters the northern tip of the Poor's Allotment section of the reserve, named in 1814 after being set apart for use of the poor of the parish. The path leads through a wooded area and meets a 0.8 mile loop, the far side of which links with a spur that descends through a larger wooded area to another entrance, along Kelly's Lane, a narrow, dead-end farm road. South of these woods is a field above calcareous soils, home to a different set of plants to the main area of heath. Again, the heath is crossed by a number of lesser trails, some coming close to a spring and short stream, a little way south of the centre. The land is fairly flat near the main road but slopes down increasingly steeply to the east, and along here are found the best views.