Families setting out on a Father’s Day walk in the Lomond Hills turned up to find drunken revellers disturbing the peace.
Police were called to the East Lomond Car Park on Sunday amid claims ravers were urinating in public and causing a nuisance by playing loud music.
It is understood the trouble makers had turned up on Saturday night for a rave and were still partying.
One walker, who left in disgust, said: “Music was being played at a very high level and I estimate I was 200 yards from the source.
“At least two people asked them to lower the volume only to be met with the threats, language and expletives you’d expect from lower-dwelling Buckfast-drinking pond life.
“There appeared to be a very high quantity of alcohol.
“Of course as a result of so much drink, there was an obvious requirement to empty bladders openly with no concerns for others including children trying to enjoy a sunny day.
“Similarly empty cans and bottles littered the small depression they had monopolised with their sound system and alcohol supply.
“I would doubt the large amount of rubbish including broken bottles would have been removed when they finished their party.”
Fife Coast and Countryside Trust said the revellers had showed no consideration for local wildlife.
Robbie Blyth, trust team leader, said: “At this time of year the Lomond Hills have nesting birds and the excessive noise levels from the rave that took place on Saturday night could affect the chicks’ chances of survival, thus impacting upon population levels.
“Additionally the local farmers have livestock currently grazing on the site and the noise levels would have caused distress and therefore the event should not have taken place on this occasion.
“In future should user groups wish to organise large events on the sites we manage I would request that they contact Fife Coast and Countryside Trust in the first instance to allow our staff to carry out an impact assessment and to liaise with other affected stakeholders.
“On a more positive note no litter was left on site.”
A spokeswoman for Police Scotland confirmed officers were called to East Lomond on Sunday following reports of anti-social behaviour.
She added: “Suitable advice was given to those in attendance and no further police action was required.”