The River Tamar rises high above the Bristol Channel coastline but flows southwards for nearly 50 miles to find the sea. It owes its name to Tamara, a nymph of Celtic legend who, along with her lover, Tavy, ended up as entwined rivers. [Torridge, her other suitor, flowed north!]

Apart from the Tavy, which flows from Dartmoor, our other main tributary is the Lynher, which rises on Bodmin Moor to the west.

The estuary is one giant drowned valley, flooded as the ice caps melted 10,000 years ago. The waters are a European Special Area of Conservation and the surrounding landscape an Area of Outstanding Natural Beauty. Every part of the river system, from the fresh water that meets the salty tide beyond Calstock to the rocky habitats provided by the mile long Plymouth Breakwater, has its own distinctive family of seaweed, worms, molluscs and fishes - hundreds of interdependent species finding their niches between moorland stream and open sea.

The juicy mudflats and the boggy, secretive saltmarshes offer just the right food and cover for many thousands of birds retreating from their northern, summer breeding grounds. The Avocet is a spectacular winter visitor for whom the Tamar [north of the bridges] and the Lynher are an internationally important site. Some 40 species of wader, duck, gull and other water birds are represented. In the summer months there are barely one tenth of the winter total, but cormorants, oystercatchers and several gull species should be easy to spot. Curlew and Shelduck are resident in good numbers. Herons always stalk the riverbanks with their smaller cousins, the all white Little Egrets.

A treat to look out for are the Grey Seals that make their way well upstream, peering above the water between feeding trips below.