The Caernarfon Coastguard helicopter airlifted the injured walker to hospital. Photo: Aberdyfi SRT

Walkers in Snowdonia used a marker plaque on a mountain fence to guide rescuers to their location after one of the group injured her ankle.

Aberdyfi Search and Rescue Team was alerted shortly after 1pm on Tuesday when the walkers called for help from Cadair Idris.

The woman, in her 50s, was with family members when she slipped on Mynydd Moel, one of the eastern peaks of the range, and injured herself.

A team spokesperson said: “The group were quickly able to confirm their location by means of a Snowdonia national park marker.

“These small discs were placed on all principal fence-crossing points across the mountain by the Snowdonia national park, and display a grid reference for that particular location.

“Given the location and the difficult nature of the extraction route for a stretcher carry, the assistance of the Coastguard helicopter, R936, was requested. The helicopter was able to land close to the casualty site, and the woman was transferred to hospital for further as-sessment and treatment.”