A pair of walkers who got lost were found by rescuers using a specialised smartphone system.
The couple were located by Longtown Mountain Rescue Team using the Sarloc system on the mountains above Abergavenny.
The walkers were rescued within an hour of raising the alarm, saving a protracted search in the dark.
The couple, from the Vale of Glamorgan, had been out walking in the mountains near the Grwyne Fawr Reservoir when they became lost as darkness fell.
The pair, in their 60s, dialled 999 and Dyfed Powys Police called out the Abergavenny-based mountain rescue team.
Neil Hughes, deputy team leader of Longtown MRT, said: “We were called out at around 8.15pm.
“The couple was well equipped and both experienced walkers. But they had forgotten to pack a torch. As darkness fell they were walking through dense forestry, in the pitch black they became disorientated and raised the alarm.
“We were able to use a system called Sarloc, developed by a former mountain rescue team member.
“The software works by sending a web link to the missing person’s phone.
“Once they click on the link their location is sent to the mountain rescue team search managers.
“We were able to get their exact location and team members went out in our 4×4 response vehicle to reach them. They were incredibly grateful to see us and couldn’t believe we had arrived so quickly.”
The system was developed by Russ Hore, former member of Ogwen Valley Mountain Rescue Organisation in Snowdonia, and has saved hundreds of lives.
Mr Hughes added: “It’s an amazing system but a mobile phone should only be used as backup to good navigation and preparation. Had there not been a good signal, allowing the system to be downloaded, then it would have been a very long night for all of us.”
The team was also called out earlier in the day after a local man was late returning from a run in the mountains above Llanbedr. He returned safely as team members were assembling.