Caving experts joined mountain rescuers to aid two people who fell down a disused mine shaft on the Llŷn Peninsula.
Aberglaslyn Mountain Rescue Team was called out on Sunday afternoon to the incident at Porth Ysgo.
Volunteer Coastguard rescue teams from Aberdaron, Abersoch and Criccieth, a Coastguard helicopter and air ambulance joined the operation, along with ambulance crew members and North Wales Cave Rescue Organisation.
An Aberglaslyn MRT spokesperson said: “Two casualties were reported to have fallen down a disused mine shaft and had become trapped. One casualty was reported to have sustained serious injuries.
“The Aberglaslyn team deployed two team vehicles to the scene to support the rescue effort, and additional members and cave rescue experts were airlifted by Rescue 936 [the Coastguard helicopter] from the team’s Porthmadog base, and flown direct to the scene.
“In a joint multi-agency rescue effort, both casualties were evacuated from the shaft with the seriously injured casualty being conveyed to Ysbyty Gwynedd by the Emergency Medical Retrieval and Transfer Service – Wales Air Ambulance.
“The team’s thoughts are with the casualty and we wish them a speedy recovery.”