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 guestbook 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." Earlier Monday, after emerging from a meeting with President Moshe Katsav, Merkel told reporters that she will tell PA President Mahmoud Abbas that he is obligated to "continue with the peace process and to do away with violence." Merkel added that she thought it was important for her to repeat that Palestinians must recognize Israel's right to existence, wherever she went. Katsav said that despite Hamas's rise to power, Abbas is still the leader of the Palestinian people. Abbas was democratically elected, said Katsav, and he has the power and influence to lead the Palestinian people in the implementation of their desires without an escalation of violence. He added that Israel still believes reconciliation with the Palestinians to be possible. Merkel also met with Foreign Minister Tzipi Livni on Monday. Jerusalem's diplomatic campaign to isolate Hamas until it changes its policies toward Israel reaped benefits Sunday night when Merkel said Berlin would have no contact with Hamas until it disavowed terrorism and recognized Israel and all agreements signed with it. Merkel, who arrived Sunday on her first trip to the Middle East since becoming chancellor in November, is scheduled to go to Ramallah Monday to relay the same message to Palestinian Authority Chairman Mahmoud Abbas. She is pointedly not meeting with Hamas representatives. Merkel was also scheduled to meet Monday with President Moshe Katsav, Likud chairman Binyamin Netanyahu and Labor Party chairman Amir Peretz. Following the press conference, Olmert hosted Merkel for dinner.