The Common is a Site of Special Scientific Interest (SSSI)[1][2] and a local nature reserve.

The common is underlain by Triassic sandstone and the varied habitats include wet and dry heaths, acidic marshy grassland and deciduous woodland with birch and oak.

[1] Thurstaston Hill is the location of Thor's Stone, a large sandstone outcrop and a place of romantic legend.

A visit to the site by members of the British Archaeological Association in 1888 heard an account by Rev.

However, geologists and historians now think that the rock is a natural formation similar to a tor, arising from periglacial weathering of the sandstone, which was later exploited by quarrymen in the 18th and 19th centuries.