Penyberth had been one of the great resting houses of the Welsh poetic tradition, a sixteenth-century farm where the cywyddwyr were said to have stopped on their travels through the Llŷn. The Air Ministry bought 250 acres in 1936 and razed it. Saunders Lewis was a founding member of Plaid Cymru and the country's most influential literary critic; his speech from the dock at the Old Bailey was published as 'Why We Burnt the Bombing School' and became one of the foundational texts of modern Welsh nationalism. He, Williams and Valentine served nine months in Wormwood Scrubs. When Lewis was released, the University College of Swansea dismissed him from his lectureship. The arson did not stop the airfield. It did, perhaps, save the language.

RAF Penrhos opened on 1 February 1937 - five months after the fire - as the home of No. 5 Armament Training Camp. The first aircraft were Westland Wallaces, lumbering general-purpose biplanes that towed drogues out over Cardigan Bay so trainee gunners could practise on a moving target. The Wallaces were soon joined by Hawker Henleys, then by Avro Ansons. A bewildering succession of units cycled through across the war years: armament training camps and stations, observers' schools, bombing and gunnery schools, service flying training schools, even a brief detachment of No. 312 (Czechoslovak) Squadron with Hawker Hurricanes. Five miles to the south-west, RAF Hell's Mouth served as the relief landing ground when Penrhos was full or fogged in.

The Czechoslovak Hurricanes of 312 Squadron arrived in late 1940 and stayed until April 1941 - a small detachment, easy to miss in the unit lists, but part of a remarkable wartime story. The Czechs had escaped their dismembered country in 1939, flown for France until France fell, and then escaped again to fight for Britain. By the time they landed at Penrhos they had become some of the most experienced fighter pilots in the RAF. They flew patrols over Liverpool Bay through one of the coldest winters of the war, then moved on. Many never went home. Communist Czechoslovakia after 1948 considered the western pilots politically suspect, and several were imprisoned or persecuted on their return.

The airfield closed on 21 October 1946, less than ten years after it had opened. But the site did not empty. The Polish Resettlement Corps took over part of the camp, using the wartime huts to house Polish soldiers, sailors and airmen who had fought alongside Britain and now had nowhere to return to - communist Poland was not a country they recognised, and many would have been arrested if they had gone back. A community formed in the buildings the bombing school had left behind. Decades later, part of RAF Penrhos still operates as an old people's home for elderly Poles, the last survivors of an exile that began in 1939 and never quite ended.

The rest of the site is now Pen-y-berth caravan park, named for the farm the burners died to save. The 400-yard tarmac strip that survived from the wartime airfield was used by private pilots through the 1980s, who flew in on summer weekends to sit in lawn chairs beside their Cessnas. Foel Fras, the small hill above the site, gives the best view: a flat green plain in the bend of the rivers Penrhos and Geirch, with caravans where the hangars stood. Three things from the original story endure here at once: the language that the burners defended, the Polish community that the airfield's death made room for, and the patch of grass where so many young air crews learned to fly into the war they did not all come back from.