A search for vital clues about a nationally important historic landscape is about to start.

Archaeologists from Durham County Council are to dig into the past at Hardwick Park, near Sedgefield, to find out how the Grade II* English Heritage listed landscape was originally designed.

At its height, the 18th century park's main attractions were a 17-acre lake, several architectural follies and a spectacular cascade.

Now the county council, with the help of the Heritage Lottery Fund and other partners, is to begin restoring the Georgian landscape to its former glory.

But before any major work starts, archaeologists are to investigate to make sure original features are protected. County archaeologist Fiona Macdonald said: "A lot of information about how the park was designed and landscaped and how the lake and its intricate water system actually worked is available from maps and contemporary documents.

"But some vital details can be retrieved only by archaeological excavation.

"Over the course of two or three weeks, we will be cutting trenches across the dam that held the lake to provide vital clues about its original construction."

She added: "We will be searching for evidence of a complicated mechanism that allowed foaming water to gush down the face of the dam.

"The Grand Terrace, which was an area for promenading, will also be investigated to see if it was paved or had a gravel surface, and the complex system of ponds and culverts that still survive in the woodland will be explored.

"The first phase of work will inform design and engineering works, while allowing original features to be protected and maintained."