Venice’s Jewish ghetto is considered the first in Europe and one of the first in the world, and a new effort is under way to preserve its 16th-century synagogues for the Jews who have remained and tourists who pass through. For nearly two years, restorers have been peeling away paint and discovering the original foundations of three of the ghetto’s synagogues, which are considered the only Renaissance synagogues still in use, art historian David Landau said. Mr Landau is spearheading a fundraising effort to restore the synagogues and nearby buildings both for Venice’s small Jewish community, which numbers around 450...