His journeys across mountain ranges and deserts opened the eyes of medieval Europe to the exotic wonders of China and the Silk Road, establishing him as one of history's greatest explorers.
But a team of archaeologists believe Marco Polo never even reached the Middle Kingdom, much less introduced pasta to Italy after bringing it back from his travels, as legend has it.
Instead they think it more likely that the Venetian merchant adventurer picked up second-hand stories of China, Japan and the Mongol Empire from Persian merchants he met on the shores of the Black Sea, thousands of miles short of the Orient.
He then cobbled them together with other scraps of information for what became a best-selling account, A Description of the World, one of the first travel books.
The archaeologists point in particular to inconsistencies and inaccuracies in his description of Kublai Khan's attempted invasions of Japan in 1274 and 1281.
"He confuses the two, mixing up details about the first expedition with those of the second. In his account of the first invasion, he describes the fleet leaving Korea and being hit by a typhoon before it reached the Japanese coast," said Daniele Petrella of the University of Naples, the leader of an Italian archaeological project in Japan."But that happened in 1281 - is it really possible that a supposed eye witness could confuse events which were seven years apart?"
Marco Polo's description of the Mongol fleet is sharply at odds with the remains of ships that the team have excavated in Japan.
The Venetian wrote of five-masted ships, when in fact they had only three masts, said Prof Petrella.
"It was during our dig that doubts began to emerge about much of what he wrote," he told the latest edition of Focus Storia, an Italian history magazine.
"When he describes Kublai Khan's fleet he talks about the pitch that was used to make ships' hulls watertight. He used the word chunam, which in Chinese and Mongol means nothing. In fact it is the Persian word for pitch. It's also odd that instead of using, as he does in most instances, local names to describe places, he used Persian terms for Mongol and Chinese place names."
The explorer claimed to have worked as an emissary to the court of Kublai Khan, but his name does not crop up in any of the surviving Mongol or Chinese records.
The Italian archaeologists' scepticism over the extent of Marco Polo's travels adds weight to a theory put forward by a British academic.
In a book published in 1995, Did Marco Polo Go to China?, Frances Wood, the head of the Chinese section at the British Library, also argued that he probably did not make it beyond the Black Sea.
She pointed out that despite being an acute observer of daily life and rituals, there is no mention in Marco Polo's chapters on China of the custom of binding women's feet, chopsticks, tea drinking, or even the Great Wall.
"There's nothing in the Venetian archives to say that the Polo family had direct contact with China at all," Dr Wood said yesterday. "Nothing from China has ever been found in the possessions they left behind.
"One theory is that Marco Polo copied a sort of guide book on China written by a Persian merchant. Only about 18 sentences in the entire manuscript are written in the first person - it is extremely rare for him to say 'I saw this with my own eyes'.
"I believe that rather than being one person's account, it's a sort of medieval database of European knowledge of the Far East at the time."