How do you define treasure? Does it sit in an old wooden chest and glint in the sunlight or is it something that provides us with knowledge about the life of our ancestors? This question is at the heart of the new exhibition at the British Museum - Buried Treasure: Finding Our Past.

“You have in the exhibition objects that if you could ever sell them would be worth millions of pounds,” says joint curator JD Hill. “But you also have objects which are utterly worthless in monetary terms but in many ways are just as important for what they can tell us.”

The exhibition hoard, which spans the Palaeolithic period to the present, ranges from trinkets, flints and coins to a gold cup from the Bronze Age, heavy-duty Roman jewels, toy guns from Tudor times and the skeleton of the Amesbury Archer. Harry Potter fans will be particularly interested in the Lewis Chessman, the walrus ivory and whale-tooth chess pieces dating back to 1150, which made an appearance in Harry Potter and the Philosopher’s Stone. Buried Treasure will be continually updated and any new finds in the UK will also be displayed at the exhibition.

Many of the items featured in Buried Treasure have been discovered by accident or by amateurs armed with metal detectors, reveals Hill. “The great thing about the exhibition,” he says, “is that all of these objects have really interesting stories of discovery behind them. As well as the stories, we explain who used the objects and why they were made in the first place.”

One story is that of the Mildenhall treasure. In the winter of 1942, Suffolk farmer Gordon Butcher was ploughing a field in Mildenhall. The plough came to a halt when he hit an unidentified object. Together with the landowner, Sidney Ford, he dug up the obstruction which they identified as pewter tableware. In all, they gathered 34 pieces, which sat on Ford’s mantelpiece until 1946 when a visiting antiquarian recognised that the collection was made of silver and was possibly of some value. The British Museum later identified the haul as one of the most important treasures of Roman silver ever found. The tale is re-told in Roald Dahl’s short story “The Mildenhall Treasure”.

The Hoxne hoard - the largest collection of Roman gold and silver found in Britain - was retrieved in 1992 by farmer Eric Lawes, who got out his metal detector to find a lost hammer. When his detector began to beep it wasn’t triggered by the hammer but by a stockpile which included 15,000 silver coins, 560 gold coins, body chains, bracelets and rings dating back to ad410-430.

Visitors can also find out about a Viking massacre, the illegal treasure hunters of Wanborough and Snettisham, and the race to date a hand-axe which could be 750,000 years old.

Collaboration between the British Museum and the National Musuem and Gallery of Wales in Cardiff, Manchester Museum, Hancock Museum in Newcastle and Norwich Castle Museum has enabled these unique archaeological finds to be displayed together. Once the exhibition ends in London, it will move on to the partner museums - all of which will be running sessions for schools.

At the British Museum, schools will be able to take part in handling sessions, listen to gallery talks every Tuesday and take part in dedicated workshops. A support pack for the exhibition is also available for key stages 2, 3, 4 and sixth-form students. Entry to Buried Treasure is free for school groups but sessions must be booked in advance with the education department on 020 7323 8511.

Buried Treasure: Finding Our Past runs from November 21 to March 14 2004 at Room 35 of the British Museum. Standard entry pound;7 for adults and pound;3 for children.Tour dates: May to September 2004, Cardiff; October 2004 to January 2005, Manchester; March to June 2005, Newcastle; July to November 2005, Norwichwww.thebritishmuseum.ac.ukburiedtreasurewww.thebritishmuseum.ac.ukc ompass For a regional listing of archaeological finds:www.finds.org