[5][6] The site is home to a number of species of birds and locally rare flora, such as Scabiosa columbaria (small scabious), milkwort and quaking grass.
[6] The caves were mined for hundreds of years for the valuable limestone, used firstly for mortar and agriculture, and then principally iron production during the Industrial Revolution.
The Victorians installed the world's first industrial steam engine next to the Wren's Nest, which pumped water from mines and access tunnels.
[6][13] In 2004, Wren's Nest and the nearby Castle Hill were declared Scheduled Ancient Monuments, as they represented the best surviving remains of the limestone industry in Dudley.
[8] The Wren's Nest's geological value was first recognised by Sir Roderick Murchison in 1839, and now both the ex-quarry and the tunnels are visited by scientists from all over the world to study its valuable content.