The Caves That Held A Secret Hungarian Aircraft Factory During World War II

The Caves That Held A Secret Hungarian Aircraft Factory During World War II

In 1944 and 1945, the Allies were attacking the last supporter of Nazi Germany. Tens of thousands of tonnes of bombs were dropped on Hungarian ground targets, mostly by the Consolidated B-24 Liberator and Boeing B-17 Flying Fortress bombers of the 15th Air Force. By the end of the World War II, the rain of incendiary and demolition bombs had wiped out all important industrial targets that fed the weakening war machine of the Third Reich — except one. The factory hiding under the 10th district of Budapest did not stop manufacturing fighter aircraft even during the most devastating air raids.

The following photos were taken in the unbelievably huge system of cellars carved into limestone rock under the breweries of Kőbánya, Budapest. Dark rooms, whitewashed, damp walls, wet passages, twisty tunnels and corridors, rusting remains of machines whisper the uncommon story of the quarries of Kőbánya. These caves were left behind by limestone miners, when the mine was finally closed in the 1890s, after a series of roof collapses. Local wineries used the caves for a short period of time, and later the Dreher Brewery bought the abandoned cellars, and used the enormous, cool tunnels for making beer.

During World War II the civil defence league built air raid shelters here, but the main function of the caves became less civilian: from March 1944, Hungarian workers assembled 1900 HP V12 engines and fuselages for Messerschmitt Bf 109 fighters, the most popular fighter aircraft in history.

According to some calculations, the underground complex is 35km long, boasting 180,000 square metres of space. The meandering corridors are 4-5m wide, branching into a variety of rooms. There are even enormous, domed halls, sometimes used as chapels. Water seeps in through the limestone walls and the mine is almost constantly wet. Small streams cross the floor everywhere, and mildew blooms along the rocky corridors. The air temperature is around 13-15 degrees, and you can see your breath as you go deeper and deeper, through the poorly lit halls.

Because the tunnels are located 10-15m below the surface (the lowest point is about 30m), the aircraft factory was protected during the last months of the war — partly because the allied bombers didn’t even know there was a military plant under the ground. As one survivor explained, they barely heard the sound of the explosions. Plus, the surface targets of carpet bombings were kilometres away.

The aircraft engine and fuselage assembly plant was so classified that only rumours existed about it for a long time. Few written documents were found by historians, and no photographs at all. We know only that the large aircraft parts were put on trucks and transported to Germany where they were assembled and sent immediately to aerial battles against US and UK forces.

The decades of socialism in Hungary brought to these tunnels the same fate as many Hungarians’ private property. Without proper maintenance, the halls deteriorated in a short time, ceilings collapsed, and groundwater engulfed lot of the structure.

Today, the vast underground complex quite often functions as a filming and bike-racing location. Its flooded tunnels and halls are being used by divers; a few companies grow mushrooms here; and Dreher still owns and uses a large part of it. Many people do not even know that the caves exist at all, and it’s only in the last few years that visitors have been allowed inside. I visited it in 2007 first time, and revisited during a special tour organised by BudapestScenes a few days ago.

(Photos: Attila Nagy/Gizmodo)