Gardaí are appealing for information after vandalism at Lough Muckno in Castleblayney.
The doors of the new changing rooms installed at the lake were forced open.
Damage was caused to the doors and their frames and locks. A number of signs in the area were also vandalised and broken.
The incident happened late on Saturday night or early on Sunday morning.
Gardaí are appealing for anyone with information to contact Castleblayney Garda Station on 042-974 7900.