Inside, it is unlike any other gallery. Rooms do not necessarily lead into each other, but take you to dead ends: you have to double back on yourself. In places, the raw concrete floors slope noticeably. Everywhere there are sharp angles and fragments of left-over space: slashes of windows reveal unexpected views of the outside world. Occasionally gratings in the ceilings and floor make you aware of rooms above and below you. Many of the grey doors are in dauntingly heavy steel. Another reference to incarceration? Certainly Libeskind refers to this work both as a "Museum with no way out" and as "Rooms against forgetting" ("Das Vergessen" or "the forgetting" is a highly-charged term in Germany, usually referring obliquely to the events of World War Two) . A light scattering of Nussbaums at intervals on the bare walls is interspersed with Libeskind's own drawings and texts: the first major exhibition will start in September.

Outside, pulled back from the entrance in the narrow prow of the building, a separate "tower gallery", small but very tall, will be used by other artists for one-off installations. Libeskind designed a path between the two, running towards the now-vanished synagogue. As the excavations for the building commenced, a complete 17th century arched stone bridge was discovered here, leading in exactly the same direction. This is just outside the old city walls and at one time, it is thought, it spanned a moat. Libeskind, delighted that his instinct had been confirmed, has included the sunken bridge in his composition, making his path a walkway over it.

The Nussbaum Museum represents a final healing of the wounds that today's inhabitants of Osnabruck, with refreshing candour, regard as wholly self-inflicted. The city once more has a Jewish community, largely made up of families from the old East Germany. With the old nearby mining and steelmaking industries in decline, there is talk of increasing tourism here, especially now the museum is ready. You are left with an irony, however. Just as Libeskind has been wrongly typecast as an architect for Jewish memorial projects, so Nussbaum, a man with no strong religious conviction, never wanted to be ghettoised as only a "Jewish artist". The next stage will be the recognition that the work of both men stands comparison with the best the 20th century offers, irrespective of its origins.