A new park, surrounding the Treasure Boat Factory Ruins, is part of Nanjing's commemoration of the adventurous admiral who set sail from the city and whose footprints still mark this ancient capital.
Many of Zheng's maiden fleet of 62 ships were built in the shipyard in Nanjing's central Gulou district near the Yangtze river, including his huge 136m-long flagship, experts say.
"Not all the boats were made in Nanjing, but we are sure that most of them were, including the treasure boats," Ma Guangru, head of Nanjing's Zheng He Research Society, told AFP, referring to the most prestigious vessels in the fleets.
"At the time Nanjing was the capital of China, the capital of the Ming Dynasty, and it was the Ming emperor who ordered the voyages, so that is why the boats were made in Nanjing and why the voyages began here."
Other boats were made in the eastern provinces of Zhejiang, Jiangxi and Fujian, he said.
Today only three of Nanjing's seven docks, where the boats were built, remain, and only one has been excavated.
During his seven voyages, the eunuch Zheng travelled as far as northern Australia and the western coast of Africa with fleets growing to more than 300 ships, many of which dwarfed the boats that Christopher Columbus would use to discover America nearly 100 years later.
Zheng travelled as far as the west
coast of Africa and north Australia
By comparison, maritime historians have marvelled at how the three ships that Columbus navigated to America could all have fit snuggly on the deck of Zheng's command ship, his nine-mast treasure boat.
Zheng's fleet was made up of many types of boats of differing sizes. Besides the bigger and more comfortable treasure boats, there were smaller vessels for soldiers, grain, supplies and horses, Ma said.
Up to 27,800 men, including sailors, clerks, officers, soldiers, artisans and doctors, sailed on the voyages that visited 37 countries from Vietnam to Africa from 1405 to 1433.
Zheng transported princesses for marriage abroad and brought diplomatic emissaries back to China.
The excavated site was opened to the public this summer as part of Nanjing's Zheng commemorations that included the rebuilding of the Tianfei Temple, dedicated to the sea goddess Mazu, that was built in 1407 after Zheng returned from his first voyage.
The temple, which was destroyed by Japanese artillery in 1937, is next to the Jinghai Temple, or temple to the calm seas, which was also built in Zheng's time and where Zheng lived late in his life when not at sea.
Visitors admire the drawings of
the famed treasure ships
Testament to this is the renaming this year of Zheng He Avenue, a road that parallels the Yangtze river and stretches from the boat yard to the temples - a route Zheng probably took regularly.
Excavations of the shipyard took place in 2003 and 2004 with many of the 1500 artifacts found kept at a museum in the park or in other museums in Nanjing and around China.
Included in the display is a 600-year-old wooden mast that is about 11m-long, several iron and bronze anchors, wooden and iron tools and plenty of old rope, wooden planks, nails and metal clasps.
Caches of tung oil were also found.
Zheng's voyages were ordered
by the Ming emperor
The oil, when mixed with lime mortar, became one of the world's first waterproofing agents for boats.
The boats were built upon wooden scaffolding in a dry dock that was flooded with water when the boat was completed and then floated onto the Yangtze river.
The ruins of the scaffolding can still be seen in the excavated pits.
The park plans to build a replica of one of the treasure boats, which should be completed by next spring, park administrators said.
China's government has largely commemorated the anniversary of Zheng's voyages - and his apparent disinterest in the conquest of faraway lands despite overwhelming naval superiority - as proof that China's 21st-century rise as a global economic and political power will come peacefully.
But for many, Zheng's exploits are a reflection of China's long-standing closed-door mentality and its failure to make better use of its powerful navy and innovations such as the compass and boat building to strengthen its global influence.
"Zheng's voyages were the result of the will of the Yongle emperor to explore the high seas, but as soon as the emperor died, exploration of the sea ended in a rather dramatic way"
Jinghai Temple curator
After the death of the Ming Yongle emperor, the mover behind the voyages, Zheng was allowed one final voyage before his fleet was grounded and Chinese maritime exploits came to a halt.
"Zheng's voyages were the result of the will of the Yongle emperor to explore the high seas, but as soon as the emperor died, exploration of the sea ended in a rather dramatic way," Feng Xiangxiang, a curator at the Jinghai Temple said.
Inward-looking bureaucrats at the time stifled the maritime industry throughout the nation and boats built over a certain size became punishable by death.
"Today we say that going into the sea was not a mistake, but due to China's feudal bureaucratic system maritime travel was stopped and from then on the nation fell behind in navigation sciences and the country became weak," Feng said.
China's failure to take advantage of its powerful navy would come back to haunt the nation during the Opium wars of the 19th century.
At that time, British gunboats forced their way up the Yangtze river and anchored not far from the site of Zheng's boat yards.
It was in the Jinghai Temple that Great Britain negotiated the 1842 Treaty of Nanking, ending the first opium war and ceding Hong Kong to Britain.