A man has been arrested after up to 150 people attended an all-night illegal rave at a Berkshire beauty spot.
Residents living nearby complained of noise coming from the gathering at Sulham Hill near Tilehurst through the night.
Thames Valley Police said its officers attended but it was not possible to disperse the people safely at night.
A 17-year-old male was arrested on suspicion of possessing an offensive weapon and cannabis possession.
He has been released while inquiries continue.
Local residents turned to social media to express anger at being kept awake through the night.
Among those tweeting, Paul Tanner posted: "What is that music noise coming from Sulham Woods ALL night and still going on? Why hasn't it been stopped?"
Police said officers "closed down" the rave in the morning.
"We are aware that a number of people in the community have been affected by noise levels from this rave and we will be reviewing the incident in order to reduce the impact on them in future."