Plashes Wood is a 71.9-hectare (178-acre) biological Site of Special Scientific Interest south of Standon in Hertfordshire.

The local planning authority is East Hertfordshire District Council.

[3] The site is mainly oak and hornbeam woodland near the northern limit of its natural distribution.

It has varied ground flora on soils from damp heavy clay to light gravels.

There are also ponds and extensive clearings dominated by bracken, and other flora including hoary cinquefoil.