Richard Nixon declared, "It really is a great wall." Zhigniew Brzezinski called out in challenge, "First one to the top gets to fight the polar bear."

Jimmy Carter, who visited China's most famous landmark this morning, had no memorable quip. But he climbed more of it than either of the others, leaving his Secret Service agents and a few hardy companions gasping for breath from the steep incline of a portion of the wall usually shunned by visitors.

It was a day of touristic achievement for the former U.S. president, in the early stages of a 10-day tour of China, his first overseas trip since leaving office. He climbed the Great Wall, ate Peking duck and ended the day watching scenes from Chinese opera at the Great Hall of the People. These three activities are among the most highly prized by the growing numbers of American tourists, estimated at 70,000 last year, who visit China.

Carter saw a sampling of his fello0w Americans at the centuries-old wall, the only man-made structure that can be seen from outer space without magnification.

"Oh my God, it's Carter," cried a surprised young woman as the ex-president and his retinue passed her.

A man from Colorado stopped Carter to offer a handshake. After identifying himself, the tourist added simply, "Thank you for making this possible," a reference to Carter's decision to normalize Sino-American relations on Jan. 1, 1979, after 30 years of estrangement.