David Hill, chairman of the Heritage Education Trust, has expressed concern at the prospect of history and other subjects being sidelined to make room for more concentrated work on literacy and numeracy.
Commenting on Education Secretary David Blunkett's recent announcement that a total of two hours a day should be dedicated to teaching reading, writing and maths, Mr Hill said: "We're anxious about the latest pronouncements for primary schools. The idea that there will be less history taught is worrying, particularly as most groups visiting museums are from primary schools."
He said it would be ironic if just when education programmes at heritage sites were being given the recognition and seriousness they deserve, the government made it more difficult for schools to justify making visits to such places.
The Sandford Awards, presented by the Heritage Education Trust to museums and heritage sites for their education programmes, was undeterred - for the moment.
For the first time this year, its panel of eight judges - educationalists, LEA inspectors, academics - have had in-service training days to enhance the quality of judging. In addition, the adjudication criteria have been tightened up. Instead of just one judge looking at a property's programme, there are now two.
And judges' reports, complete with recommendations, are being shared with the properties, with a view to improving standards.
Glamis Castle in Angus, Scotland is the recipient of theonly full Sandford Award for 1997. Its two-year-old education programme features a restored cottage in the nearby village, which school groups use as a base from which to visit the castle or the 18th-century Glamis village, with its Angus Folk Museum and the Christian Heritage Trail.
An education pack, written by two primary teachers, covers the castle, the castle grounds, management of the estate and the coach house.
Three thousand schoolchildren visited the castle last year. Administrator Lt Col Patrick Cardwell Moore is concerned about "schools having so little money they can't afford these kinds of visits".
He says: "We want to give children the opportunity to experience their natural and historical heritage."
All properties winning Sandford Awards are reviewed every five years and if their high standards are sustained, they are presented with a Quinquennial Award.
This year, eight museums, castles and heritage sites received these awards. Recipient of the Reed Award, given to sites which show good practice in their work with children who have special needs, is Ford Green Hall of Stoke on Trent. It collaborated on a two month project with teacher Gill McGillan of Middlehurst Special School.
Children from Years 5 and 6 were able to enhance their study of life in Tudor England by visiting the museum in costume, examining artefacts and participating in dance and music of the period.
A follow-up visit by museum assistant Clive Hollinshead focused on the local environment and particularly on life in the potteries in Tudor times.
School and museum staff said the children got tremendous enjoyment and understanding from it, and the museum received its Reed Award only a year after getting a Sandford Award.
But Clive Hollinshead said he also had fears for the future. As well as having had to introduce afternoon entrance fees last April after funding cuts at the new unitary authority of Stoke on Trent, the numeracy and literacy hours could be another blow: "A lot of heritage centres providing for schools will find a drop in numbers. It's inevitable. But nobody knows how serious it will be until it happens."