Tucked behind an allée in Neustadt, a late-nineteenth-century neighbourhood in Mainz, is a new, shimmering, sculptural Jewish Community Centre. It was built on the site of the city’s former main synagoge, which was destroyed in the Kristalnacht (1938). Along the street, the building, recalling a meandering ribbon creased at intervals, responds to the perimeter-block fabric. At the site’s east side,...