A popular beauty spot has been ruined by strangers meeting up to have sex, according to people living nearby.
Up to 40 cars a day park up at Stapleford Wood, south of Lincoln.
The drivers – usually in smart business clothes and expensive cars – disappear into the wood for sexual liaisons.
When they drive off, they leave behind condoms, pornography and knickers, which is now deterring families from visiting the woods.
As well as strangers meeting for sex, another problem for the authorities is "dogging", where people turn up to watch others having sex.
North Kesteven District Council tried to tackle the problem with a day of action at the woods.
Boulders were also put in parking and turning areas to put off the "doggers" at the Forestry Commission-owned site.
Police patrols have also increased, but locals say the issue has got so bad they now don't even bother reporting it.
Ray Philips, county councillor for the area, said: "People now don't want to go there.
"It is really getting out of hand. There is a constant stream of cars. I think the concern is the Forestry Commission don't seem too concerned about it."
The problem has grown because many dogging websites name Stapleford Wood as a popular place to meet up.
And the activity is not just at night-time. Even in daylight hours, the drivers are meeting up. One resident, who asked not to be named, said: "We used to make complaints to the police but there is no point any more. It's quite intimidating when there are a lot of them. They sit there staring at you.
"It's sordid. I used to take my granddaughter there but I wouldn't do that now. You don't know what you will find, or who you might find."
When the Echo visited the woods we saw luxury cars, people emerging from the undergrowth and groups congregating around vehicles.
Two men in smart clothes were seen leaving the wooded area, off the main paths, together and returning to separate cars.
Inspector Mike Jones, of Lincolnshire Police, said efforts to block up popular parking spots had been an effective deterrent.
"We're having as much success as anyone else in the country in dealing with this problem," he said.
Nigel Lowthrop, owner of nearby social enterprise Hill Holt Wood, wants to take over management of the forest. He thinks this would help curb the problem.
"It's got worse," he said. "It's horrendous. It puts off a lot of parents and you wouldn't expect children to go there."
Richard Darn, a spokesman for the Forestry Commission, said the body was taking steps to improve the situation.
He said: "I think it's a case of working hard at this but I don't think there is a magic bullet.
"No-one can be there 24/7 to patrol a woodland that size."