A wildfire that scorched the coast of Ireland has revealed a World War II-era sign carved into the ground. Irish police officers spotted it while flying over Bray Head to assess the fire’s damage.

The partially-eroded sign originally said “ÉIRE,” which means “Ireland” in the Irish Gaelic language. During WWII, over 80 of these signs along Ireland’s coastlines signaled to bombers that they were flying over neutral territory and shouldn’t attack.

Ireland’s police force tweeted that it’s seen these WWII signs in other places, but hadn’t spied this one before. It appears that gorse and other undergrowth obscured the sign until the recent wildfire burned it away, revealing the white-washed message beneath.

Before WWII even broke out, Ireland maintained that it wouldn’t join any war Great Britain entered. This was partially a way for the state to assert its independence from Britain.

Ireland seemed to uphold this promise when Europe plunged into war in 1939. Yet secretly, it provided support to the Britain’s Allied Powers. Ireland interned German airmen and sailors who landed on its territory while allowing British troops to return to Britain. In addition, around 43,000 Irish people joined the British forces.

“Other un-neutral measures included transmission to the British of information on German aircraft and submarines off our coast,” reported The Irish Times in 1999. Ireland had an anti-submarine radar station, and allowed Britain to attack enemy submarines in its waters. The state also let Britain use logistically-important locations and fly in its airspace.

The war’s carnage reached Irish shores during the Belfast Blitz in April and May 1941. The German Luftwaffe bombed the city of Belfast, killing over 1,000 people and causing tens of thousands of others to flee.

The WWII sign is the just latest discovery made in Ireland this summer because of the hot, dry weather. Ireland’s heatwave has also led to the discovery of the supposed home of St. Oliver Plunkett, a Roman Catholic martyr, and the discovery via drone of an ancient “henge” dating to 3,500 B.C.E.