Location
The NNR is located in north-west Hampshire on the borders of Wiltshire and Dorset, 1 mile west of Martin village. The main car park is signposted from the A354 approximately 12 miles south west of Salisbury
Site
Although one of the largest areas of chalk grassland in the country, Martin Down represents a small remnant of the downland which once covered the chalk. The site includes grassland habitats, together with scrub and woodland, supporting a wide range of downland flowers, insects and birds. This patchwork of habitats has developed over hundreds of years as a result of the influence of man's activities on the natural vegetation of the chalk.
Farmers from the Neolithic age onwards (5,000 years ago) cleared woodland for cultivation. Cleared areas were grazed by animals and, over time, became grassland. Common grazing rights exist on Martin Down today, as they have done since mediaeval times. Traditionally, sheep grazed the downs by day and were moved to arable fields at night. Martin Down was not enclosed and remains an extensive area of grassland surrounded by agricultural land.