On the night of 4-5 September back in 1942, 251 bombers took off from Syerston Airfield in England. One of them, a Lancaster R5682, was shot down above the Wadden Islands and crashed into De Alde Feanen, near Warten. Five of the seven crew members managed to parachute out of the aircraft. One did not survive the fall, while the other four men were taken prisoner of war. One body of the two occupants was later found, but the last person, tail gunner Francis Cooper, could not be found after the crash.

Cooper’s body was finally discovered seventy-five years later, when salvage of the aircraft began in 2017.

A permanent memorial site has been created at the spot where the Lancaster crashed: De Zwaluwhaven. This 32-metre long wall, designed by landscape architect Nynke Rixt Jukema, has 251 holes for sand martins to make nests in. This number corresponds to the number of fighter planes that took off that fateful night in September 1942. The length of the wall corresponds to the length of the Lancaster. Twelve of the 251 holes are closed, representing twelve planes that took off in 1942 but never returned.

De Zwaluwhaven was opened on 15 April 2018, an important date since it is the anniversary of the liberation of Friesland in 1945. 39 surviving relatives of the pilots and crew members were present at the unveiling of the monument. On 15 April 2018, an exhibition about the Lancaster and the Zwaluwhaven will open in De Alde Feanen Visitor Centre in Earnewâld. Please note: the exhibition closes on July 17, 2023.