A Sheffield couple have had to surround their garden with barbed wire and install CCTV after being plagued by crime and vandalism from an adjoining nature reserve.
Jan and Steve Peel, who have lived on Worrall Road for 18 years, said they did not want to turn their garden into a fortress, but had no choice after criminals stole and burned their property.
Their three-and-a-half-acre garden runs into the common, and was not fenced off until this year.
In June last year, criminals dragged their garden furniture through thick brambles and set it alight in a hollow in the woods.
They also burned and destroyed their greenhouse, which they had recently set up.
The thieves had cut branches off trees to start the fire. A vodka bottle and more than two dozen cans of lager were found next to the fire site.
Only two weeks later, Mrs Peel, a retired landscape architect, found several more youths hanging out in the hollow.
"I wasn't going to approach them at all, but I went up to check on them and one of them threw a can down where a couple of other cans had been thrown," she said.
"So quite diplomatically I said: 'You'd better move on now.'"
"But they went mad and one of them tipped a full can of beer and just emptied it over my head," she said.
"I was absolutely drenched in beer. There was a moment where it seemed he was going to hit me and I just screamed.
"He did eventually go but not without putting his trousers down to his ankles three times and mooning me," she said.
One man was arrested, but the case never went to court after Mrs Peel failed to identify him at a line-up six months later.
In July, 30 to 40 young people camped on a field in the common, leaving behind a tent and a large number of used condoms.
Later the same month, a Rotavator, a large machine for digging earth, was stolen from Mr and Mrs Peel's garden.
"A neighbour reckoned it would take six strong blokes to shift it. The creepy thing is they must have been watching to see me go out and then go take it," Mrs Peel said.
Mr Peel said the machine would have been worth only about £20 in scrap metal.
Trouble on the Common has continued ever since, especially with young people camping and starting fires in the woods.
Because of high temperatures early this year, Mr and Mrs Peel are now afraid criminal activity will continue this summer. In February, they found a black sack full of discarded cannabis leaves in the woods.
In response to the criminality, Mr and Mrs Peel have put up a barbed wire fence around part of their garden and set up a CCTV system.
But two weeks ago young men still managed to get into the garden, and smashed up several nest boxes. When they found out a CCTV camera was watching them, they stole it.
Mrs Peel said: "We don't want to turn the place into a fortress, but on the other hand last summer we couldn't even go out for a cup of coffee."
"There are so many of them and they are so drunk and so drugged up to the eyeballs that they don't know what they're doing."
Police Sergeant John Kirkham, part of the Hillsborough Safer Neighbourhoods Team, said: "There are currently patrols in the area. Young people will go to such parks to try to chill out together."
Richard Saunders, the Ranger responsible for the common, said the problems were a police matter.
Despite all the trouble, Mr and Mrs Peel have tried to make their garden a safe haven for different plant and animal species. This year, they have spotted badgers and a wheatear, a fairly rare migratory bird.
"It's an amazing place, and it really, really needs to be kept," Mrs Peel said.