ACTIVITIES are being organised to celebrate the natural wonders of an estuary's mud-flats and marshes.

English Nature, Hartlepool countryside wardens and the staff of Teesmouth Field Centre have joined together to run events this weekend, inviting the public to Teesmouth National Nature Reserve, to mark annual Low Tide Day.

Tina Flinn, of English Nature, said: "At low tide, you can see a large area of mud-flats at Seal Sands. These are the largest expanse of inter-tidal habitat between the Humber Estuary and Lindisfarne. Over 20,000 birds visit Teesmouth during one year, including shelduck, teal, knot, ringed plover, snipe, curlew and redshank."

On Saturday and Sunday, there will be hour-long seal watches at 10am and 11am. During the afternoons, there will be a walk, from 1pm to 3pm, around North Gare when a guide will talk about the Zinc Works Road village, which had its own hospital.

For more details, call (01429) 853325. Booking is essential.