Before I entered the Holocaust Museum in Jerusalem, I had to walk down a boulevard called "The Avenue of the Righteous Gentiles." It is lined with hundreds of trees planted in honor of people who sheltered or in other ways assisted Jews during the Nazi regime. At the base of each tree is a metal plaque bearing the name of a man, woman, or family who risked their lives to help Jews during the Holocaust. Some of the names are familiar, like Corrie ten Boom and Oscar Schindler. But most are not.