For sale: One U-boat pen, slightly used

A vast concrete complex built by slave labour on the North German coast and known as Valentin may not be a des res but the former submarine factory is up for sale to anyone interested in a building with 7m-thick walls. It is the largest surviving bunker from the Third Reich. The asking price is vague but government officials say that they could be accommodating for any serious bidder. The place has become a millstone, its upkeep swallowing up to €800,000 (£630,000) a year from the Defence Ministry budget. “And that's just the absolutely essential investments needed to stop the place crumbling,” says commandant Wolfgang zu Putlitz, who is in charge of guarding and maintaining the site.

Hitler, concerned that Germany was losing the edge in the war for the sea lanes, ordered the construction of the factory near Bremen with the aim of producing a new U-boat, the sophisticated XXI model, every 56 hours. The factory was a silo with the dimensions of a cathedral: 426m (1,400ft) long, 97m wide, 25m high. At one end was a diving basin for the last tests on the U-boats before they would slide into the Weser river and head for the North Sea. In the event, no submarine left the factory. By March 1945 the factory, begun 18 months earlier, was 80 per cent complete. Then a British Bomber Command raid succeeded in penetrating the roof using the 10 ton Grand Slam bomb (The above photo shows the result of the bombng). Before repairs were complete, the war was over.

The initial idea after the war was to blow up Valentin but that would have required at least 500 tonnes of explosives and the blast would have wiped out most of the neighbourhood. So it was taken over by the German Army, which has been using part of it as a storehouse. Blowing it up is now out of the question because it has been officially listed: research in Eastern European archives has shown that at least 4,000 slave labourers, many of them from Poland and Russia, died building Valentin. Most were undernourished. Some were beaten to death by guards trying to enforce a breakneck speed of construction.

“This bunker should not be sold,” the Mayor of Bremen, Jens Böhrnsen, says, “for both financial and moral reasons.” The new owner would have to commit himself to making at least part of the site into a memorial centre for Nazi slave labour. At least 12,000 concentration camp inmates, forced labourers and prisoners of war were involved in the project: a million tonnes of gravel and sand had to be dug up and 1,232,000 tonnes of cement was mixed.

Franz Josef Jung, the German Defence Minister, has said that he is aware of the historical significance of the U-boat factory but added: “It is not the task of the German Army to maintain memorials”.