These six sites are located along a 12 km section of the River Clyde and its tributaries, and lie close to built-up areas such as Hamilton and Lanark on the southern outskirts of Greater Glasgow.

[4] At the Falls of Clyde in particular there are endangered peregrine falcons and rare tundra plant life that has survived on a cliff face since the last Ice Age.

[1] There is also a Special Area of Conservation (SAC) entitled Clyde Valley Woods, which covers 437 ha (1.7 sq mi) of land and partly overlaps with the NNR.

The higher parts of the woodlands have a more acidic soil, and are home to species such as oak, birch, hazel, Scots pine and occasional stands of aspen.

[11] Many of the elm, hazel and oak trees at the northern edge of Cleghorn Glen were coppiced between the early 19th and mid-20th centuries to provide wood for a variety of purposes including charcoal, pit props and products such as clogs and bobbins for the cotton mills at New Lanark.

Of the birds present, the most notable are the spotted flycatcher, bullfinch and song thrush, all of which are identified as priority species in the United Kingdom Biodiversity Action Plan.

[14] Jerviswood, on the edge of Cleghorn Glen, features in the Lanark Lanimers celebrations, as birks (birch twigs) from here are carried as part of the procession.

Within the Falls of Clyde site there is an abundance of architecture, including Bonnington Pavilion,[17] an 18th-century house of mirrors, an iron footbridge,[18] and the 15th-century Corra Castle, all of which are in ruins.

Part of the site is classified as a SSSI, although the NNR extends further to include most of the land along the Avon Water and Meikle Glen within the estate.

[23][25] Lower Nethan Gorge, located near the village of Crossford, is a semi-natural woodland consisting chiefly of elm, ash and oak trees.

The site is particularly noted for a number of uncommon beetles including the nationally scarce species Cerylon fagi, Tetratoma ancora and Ptinomorphus imperialis.