Gustav August Munzer's design was chosen from the 1927 competition — the formal first prize actually went to a rival entry, Heinz Stoffregen's, but the judges preferred Munzer's concept and had it built in simplified form — with a shape nobody has ever agreed on. Guides point out the stem of a Viking longship. Sailors see a submarine's conning tower. Munzer rejected both readings, describing instead a form rooted in earth and sea and rising toward the sky like a flame — expressionist architecture in brick and concrete, built at a scale that lets it be seen from most of Kiel Fjord. The shell went up fast, in barely a hundred days, though the surrounding complex took until 1936 to finish. The tower stands 72 metres tall, and because the ground under it is already raised, the observation deck ends up 85 metres above the Baltic. Two lifts run to the top. So do 341 steps, and a surprising number of visitors take them.

The memorial was formally inaugurated on 30 May 1936. Adolf Hitler attended, watching a naval review from the aviso Grille while the sail training ship Gorch Fock rendered honours offshore. A monument conceived in the Weimar years by the Deutscher Marinebund — a veterans' association — was handed its public meaning by a government already rebuilding the navy Scheer had mourned. That is the uncomfortable fact at the centre of the site, and Laboe does not pretend otherwise. The tower was not built by the Nazi state, but it was consecrated by it, and the men it commemorated in 1936 were being invoked as an argument for the war that followed.

In 1945 the Royal Navy took the complex over and expelled the Marinebund. The Allies handed it back in 1954, but with a condition attached: the memorial had to widen. The new dedication read "Dem Gedenken aller toten deutschen Seefahrer beider Weltkriege und unserer toten Gegner" — to the memory of all German seafarers who died in both world wars, and of our dead opponents. Those last four words did most of the work. In 1996 the dedication opened further still, to sailors of every nation lost at sea, and to peaceful seafaring on free seas. Plaques have accumulated: the German Navy remembers its own dead since 1955, another honours civilians killed in disasters at sea, and one commemorates American submariners still on patrol. Between 1954 and 2004 more than fourteen million people came through.

Then there is U-995, hauled up onto the sand below the tower, grey and improbably small. She is a Type VIIC/41, commissioned on 16 September 1943, and she made nine war patrols in Arctic waters under two commanders, Walter Köhntopp and then Hans-Georg Hess. At the surrender she was at Trondheim. Norway took her, commissioned her as Kaura in 1952, and ran her until 1965. She is the only Type VII left anywhere in the world — the workhorse hull of the Battle of the Atlantic, the class that fought and mostly died in the North Atlantic convoy war. Go below and the abstraction collapses. The passage is narrow enough to catch your shoulders. Bunks share space with torpedoes. Every surface is a valve, a gauge, a handwheel. Whatever you thought about the U-boat campaign before you climbed down the ladder, the physical smallness of the thing rearranges it.

The view from 85 metres is worth the climb regardless of what brought you. Kiel Fjord runs south toward the city and the naval base; ferries work the water below; on a clear day the Danish coast is a suggestion on the horizon. Laboe itself is a modest seaside town, all beach huts and ice cream, and the contrast is part of the experience — holidaymakers on the sand, a submarine parked beside them, and above both a tower that has been asked three times to mean something different. Few memorials wear their own revisions so openly. That, more than the architecture, is the reason to come.