Pink Floyd drummer Nick Mason opened up his gardens to the public for the first time in nearly 20 years this weekend.

Camilla, Duchess of Cornwall, and her former husband Andrew Parker Bowles both returned on Sunday, separately, to visit their former Corsham home, which was sold to Mr Mason and his wife Annette in 1995.

The open gardens event was to raise money for Wiltshire Air Ambulance Appeal and the Bobby Van Trust, for which Camilla is a patron.

About 900 people visited Middlewick House yesterday, and today was said to be even busier.

There was plenty to explore, with six different garden areas plus a couple of paddocks with horses among the buttercups, two riding arenas, a football pitch, a tennis court, a woodland and a ‘conservatory’ containing a swimming pool and Jacuzzi.

A sign saying Cary and Guy’s House stood next to the Masons’ sons’ impressive treehouse - an actual wooden hut built into the tree complete with wooden staircase and rope ladder.

The grounds were also a playground for Mr Mason, with a selection of his 40 classic cars dotted around. They included a 1930 Bentley, Austin Seven, Ferrari Gti, Alfa Romeo 8C Competizione, and Jaguar Mark 2. The trees’ helicopter seeds covered the bonnets gleaming in the sunlight.

Bronze sculptures on loan from artist Simon Gudgeon included a £30,000 pheasant, of which only five exist. Mr Mason said he would be keeping one of the sculptures and his favourite was the swans on the pond.

Hugh Trethowan, 60, who was visiting from Bath, said: “Oh I didn’t expect to see Nick, I thought he would have gone off in his helicopter for the day.”

Chris Chappell, 56, from Southwick, near Trowbridge, said: “I like how some of the gardens have been left quite wild.”

Camilla arrived chauffeured in an Audi, with a Land Rover and BMW in her entourage. She was welcomed by Mr and Mrs Mason and her close friend Lady Lansdowne, who lives nearby at the Bowood country house estate.

Dressed in a navy summer dress and closed toe tan wedges, the beaming Duchess was given a guided tour, fed the piglets and said she liked the new arches in the original kitchen garden.

It is a full time job for gardener Frank Powell, who has been doing the job 17 years and said it had not changed much except for extending the pond.

Mr Mason said they inherited a lovely garden from Camilla and Mr Parker Bowles and thought opening it up for the weekend would be a good excuse to get it tidy.

Inside his home he has a Drum Workshop kit, and a grand piano which he said no one in the family really played. “It’s just for visitors really,” he said. “Roger [Pink Floyd bassist Roger Waters] comes around sometimes; I was at his daughter’s wedding [model India Waters] last week.”

He said there were currently no plans for another tour.

Not many people want to live next door to a drummer, but Guy Stafford said Mr Mason is a fantastic neighbour.

“He bought some of the woodland off me,” he said. “And we let Annette ride the horses around our farm.”

He has lived since birth in his house, which he said was bigger than the Masons’. He said he remembers Camilla and Mr Parker Bowles as lovely neighbours too and they sent their children to Heywood Prep School together.

“When Camilla lived here, I used to get snapped coming home in my Range Rover because they thought it was Charles coming in,” he said.

Caroline Corrigan, head of fundraising for Wiltshire Air Ambulance, said: “Nick and Annette have been amazing hosts and we’re pleased to see our helicopter is bigger than theirs!

“We really appreciate their and Camilla’s support because we’ll be needing to lease our own helicopter when our partnership with the police runs out next year, so we need to raise our fundraising from £700,000 to £2.5 million.

“It’s been such a busy weekend. We thought we had enough cakes for two days but we’d run out by 2pm on Saturday, so we had volunteers frantically baking more."