The air ambulance was called after a medical emergency in Ynys Enlli (Bardsey Island).
Emergency services were alerted to the incident on the island, located about three kilometers off the Llŷn peninsula, on Tuesday afternoon.
A patient was taken to hospital for treatment.
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A spokesperson for the Welsh Ambulance Service said: “We were called on Tuesday June 29 at around 4 pm to report that a person needed urgent medical attention on Bardsey Island.
“We responded with an emergency ambulance and received support from the Wales Air Ambulance.
“A patient was transported by air ambulance to Ysbyty Gwynedd. “
The nature of the medical emergency and the patient’s condition were not disclosed.
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The island is managed by the Bardsey Island Trust and is designated a National Nature Reserve and Site of Special Scientific Interest.
It has also been classified as a Special Area of Conservation for its habitats and species, as well as a Special Protection Area due to nesting birds.
Most of the island’s 12 properties are vacation rental.
The island is known as the “Island of 20,000 Saints”, with confidence indicating that the name dates back to the early Middle Ages, when three pilgrimages to Ynys Enlli amounted to one pilgrimage to Rome.
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