What did Marco Polo like about on his visit to the wall of China?

Marco Polo admired the Great Wall of China for its impressive scale and engineering. He noted how it was a formidable barrier against invasions and a testament to the strength and determination of the Chinese people. Polo was particularly impressed by the wall's construction and the strategic points along it, which showcased the sophistication of Chinese military architecture. Overall, he found it a remarkable feat of human ingenuity.