Thorpe Park No 1 Gravel Pit is a 42.5-hectare (105-acre) biological Site of Special Scientific Interest (SSSI) east of Virginia Water in Surrey.

This former gravel pit has been designated an SSSI because it is nationally important for wintering gadwall.

There are also several other species of wintering wildfowl, such as goldeneyes and smew.

[4][5] The British Trust for Ornithology noted a Wetlands Advisory Service report of 2003 that suggested recreational activities at the site might have contributed to a decline in recorded gadwall numbers.

[6] The site is used for waterskiing but the activity is prohibited between 1 October – 31 March, which is the period when the gadwalls use it for feeding.