Bikers have been slammed for damaging ground at a nature reserve in East Durham.
The damage was caused at Warren House in Horden, with dirt tracks left in a number of locations at the site.
Flowers have also been destroyed by the yobs, with police informed about the incident.
A post on the Durham Coast and Countryside Facebook page reads: "During a visit to Warren House Dene, Horden, our rangers were devastated to discover extensive damage caused by motorbikes.
"The site has been carefully managed for several years and had become the best habitat on the coast for the rare Durham Argus butterfly.
"Rangers estimate that up to two thirds of the site has been damaged, with most of the common rock rose (vital to the Durham Argus) they had planted being destroyed.
"Parts of the Durham Heritage Coast footpath along the bottom of the dene have also been damaged.
"We are working closely with the police to tackle issues of anti-social behaviour such as this.
"If you'd like to volunteer to help restore this lost habitat and lend a hand with other nature conservation work on the coast, please contact area ranger Mark Frain: email firstname.lastname@example.org or call 07483 117 657."