Wren's Nest

Wren's Nest
Fossilized ripple markings at Wren's Nest
Location of Wren's Nest within the West Midlands
Type	Nature reserve
Location	Dudley, West Midlands, England
OS grid	SO937921
Coordinates	52°31′34″N 2°05′37″W / 52.526°N 2.0936°W / 52.526; -2.0936Coordinates: 52°31′34″N 2°05′37″W / 52.526°N 2.0936°W / 52.526; -2.0936
Created	1956 (1956)
Operated by	Dudley Metropolitan Borough Council
Open	All year
Website	link

The Wren's Nest is a geological Site of Special Scientific Interest in the Dudley Metropolitan Borough, north west of the town centre of Dudley, in the West Midlands of England. It is one of the most important geological locations in Britain. It is also a Local Nature Reserve, a national nature reserve (NNR) and Scheduled Ancient Monument. The site is home to a number of species of birds and locally rare flora, such as Small Scabious, Milkwort and Quaking Grass. The caverns are also a nationally important hibernation site for seven different species of bat.

The Wren's Nest National Nature Reserve is world-famous geologically for its well-preserved Silurian coral reef fossils. Considered the most diverse and abundant fossil site in the British Isles, more than 700 types of fossil have been found at the site, 86 of which are unique to the location, including Calymene blumenbachii, a trilobite nicknamed the Dudley Bug or Dudley Locust by 18th century quarrymen. An image of this trilobite featured on the town's coat of arms until 1974.

The limestone outcrops belong to the Wenlock Group, which was formed some 420 to 425 million years ago from the material remnants of an ancient tropical sea bed, and contain ripple marks made from the sea's action on the sand. Wren's Nest Hill was extensively quarried during the Industrial Revolution for building stone and lime production. The site was originally studied by the Scottish paleontologist Sir Roderick Murchison, whose work in defining the Silurian System was mainly based on fossils and rock formations found at the site.