The events of the Holocaust were "a source of deep shame" for Germans, German Chancellor Angela Merkel declared on a visit to the Yad Vashem Holocaust Memorial on Monday. "[Germans] are grateful that the staff at the museum included the stories of the righteous among the nations, even though they were too few. Nevertheless," she told Yad Vashem chairman Avner Shalev and others who accompanied her on her first visit to the memorial, "this fact challenges us to learn from history." Shalev, who guided Merkel through the Holocaust History Museum, also accompanied her as she laid a wreath in a moving ceremony at the Hall of Remembrance. Merkel then proceeded to the Children's Memorial, after which she spoke briefly in German. "Here at Yad Vashem," she said, "I want to stress what I stressed to various parties in diplomatic discussions: the friendly relations between Germany and Israel, and particularly the special friendship that has developed between our peoples. For us Germans the relationship between Germany and Israel will remain special, and we are grateful for it." Before leaving, Merkel signed the Yad Vashem guest book with a quote from 19th century explorer, scientist and patron Alexander von Humboldt. "Only those who know the past," she wrote in German, "have a future."