The site has only been visible three times in the 77 years since the crash (Picture: Joseph Mearman/Bangor University).
The crash site of an American Second World War fighter plane has been given protected status - 77 years after it came down.
The Lockheed P-38 Lightning, also known as the Maid of Harlech, crash-landed in the sea off the north Welsh coast in September 1942.
Cadw, the Welsh Government's historic environment service, has declared the crash site a scheduled monument due to its historic and archaeological interest.
It says the Maid of Harlech is the first military aircraft crash site in the UK to receive protected status of this kind.
The aircraft's preserved hull is two metres beneath the seabed and unfavourable conditions have meant it has only been visible three times since the crash - in the 1970s, 2007 and 2014.
The pilot, Second Lieutenant Robert F Elliott, was 24 when the aircraft came down on a gunner practice mission from Llanbedr in Gwynedd, North Wales.
The Californian survived the crash-landing but was reported missing in action a few months later while serving in Tunisia.
His nephew, Robert Elliott, is a retired US Navy veteran and a member of the 49th Fighter Squadron Association and was "honoured and delighted" by the recognition.
Having visited the site in 2016, Mr Elliot said: "My uncle was among those brave and expert fighter pilots who served with distinction during World War Two."
Matt Rimmer, a local aviation historian, said the protection of the site acknowledges "the important role played by Wales in the air war against Nazi Germany".