Hundreds of visitors flocked to Gayton Hall on Sunday to wander around its 20 acres of water gardens.
The Mother’s Day event marked the 90th anniversary of the National Gardens Scheme, of which the hall is one of more than 3,700 members.
One of the schemes’ Norfolk county organisers, Julia Stafford Allen, said the hall first opened its doors to the public in 1939, shortly before the outbreak of the Second World War, raising £8.
After that, it was not until 1979 that the gardens were again opened to visitors.
But, since then, it has become an annual event which, so far, has raised more than £22,000.
The money is shared between Macmillan Cancer Support, Marie Curie Cancer Care and Hospice UK, three of nine nursing charities the scheme supports nationally.
Mrs Stafford Allen said: “We have 65 open gardens in Norfolk.
“They raise about £10,000 a year for charity. Nationally the scheme raises £3.5 million.”
A canopy of trees covers most of a circular half hour walk around lakes, streams, carpets of daffodils and narcissus and over small bridges.
The hall was built at the beginning of the 19th century but many of the trees that now cover the grounds were planted since 1979 by the Earl of Romney.
The Earl recently moved out of the hall, which is now the home of his son, the Viscount, and Viscountess Marsham.