Police were called to an illegal rave last night which was attended by around 200 people .
Dyfed-Powys Police were notified of the rave taking place at the Usk Reservoir area in the western part of Bannau Brycheiniog, approximately 16 miles west of Brecon.
Police were called at around 9:30pm yesterday (Saturday).
Officers attended to find approximately 200 people in attendance, with 70 or 80 cars on the site.
Police closed roads leading to the site with the support of local authority highways.
The illegal gathering began winding down at around 6am.
One person was taken to hospital by ambulance.
No arrests have been made, however, enquiries are ongoing.
This morning a multi-agency meeting was held with key partners affected by the illegal gathering.
A spokesperson for Dyfed-Powys Police said: "We would urge people living in rural communities, including farmers and landowners, to report anything suspicious to police.
"The information would help police respond swiftly as illegal raves arise and hopefully prevent them from happening or at the very least allow police to respond before they become established.