Local police are clamping down on anti-social and dangerous behaviour in woodland outside Llandudno, part of the Mostyn Estate.
Youths have been lighting fires which have damaged ancient trees, dug holes, left rubbish strewn around, while loud amplified music is disturbing nearby residents.
PC Lee Openshaw, Llandudno Community Beat Manager, says the gatherings have been advertised via social media. The anti-social behaviour and fire lighting not only damage the ancient woodland, but also put the young people involved at risk.
There have been meetings with Mostyn Estate representatives, and the police will be conducting patrols and will deal robustly with any anti-social behaviour.