'It may sound ridiculous to you that a palace could become factories and a market. But that was China then. No one cared about history,' said Mr Wang Bin, vice-director of the museum.
EARTHLY TOILS OF SON OF HEAVEN
Pu Yi was made emperor of China when he was barely three years old. But three years later, in 1912, the Qing Dynasty son of heaven was forced to abdicate after a republican revolution ended imperial rule.
But the last monarch, an ethnic Manchu, harboured dreams of returning to the throne.
When the Japanese promised him a renewed regal life, he took up their offer in 1932 and became emperor of Manchukuo, a puppet state in north-eastern China, formerly Manchuria, where the Qing rulers originated.
It panned out poorly. Although a palace was built for him in Changchun in present-day Jilin province, he had no power to decide anything, including the choice of concubines. The Japanese even forced him to wear Western military uniform instead of his preferred Manchu robes.
When World War II ended in 1945, he was captured by Soviet troops and spent years in Siberia, where he pleaded with Stalin to let him stay, fearful that he would be executed in China for his traitorous partnership with Japan.
But he was returned to China five years later and imprisoned for a decade. He worked as a gardener upon his release, dying as a commoner in Beijing in 1967 from kidney cancer. He was 61.
Peh Shing Huei
This is China's other palace. Unlike the world-famous Forbidden City in Beijing, the Changchun mansion was set up for Pu Yi when he ruled Manchukuo, a puppet state of the conquering imperial Japan in north-eastern China, for 13 years from 1932.
Now, after three decades of painstaking restoration, clearing the palace of illegal squatters and years of national shame, it is finally worthy of its imperial name.
And in the centennial of Pu Yi's 1912 abdication, the palace is aiming to be a major tourist attraction and even a global icon for peace.
It has far to go. It draws just a million visitors, mostly Chinese, a year, compared to about 130 million who visit the much larger Forbidden City.
To get the turnstiles going, it plans to spread its name overseas vigorously.
Exhibits of Pu Yi have already been shown in Japan, with more lined up in other countries.
The palace will have a theme of peace, as a counterpoint to its history of colonialism and war.
'We want to be a world education centre, much like Auschwitz,' said Mr Wang, referring to the Nazi concentration camp.
'It has done a great job promoting itself. Everyone who goes to Poland must visit it.'
Just like Auschwitz, the palace lies on the wrong side of history. Its official Chinese name translates literally as 'The Illegitimate Manchukuo Imperial Palace Museum'.
'Such negative icons of China's history have largely been destroyed. This palace is one of the few such architectural structures which have survived intact,' said Mr Jia Yinghua, the country's best known Pu Yi researcher.
The museum also hopes to beef up its displays and is scouring the world to recover treasures that once belonged to the emperor and the palace.
Much was lost after the Japanese were defeated in World War II in 1945. Pu Yi fled and was captured by the Russians, but his palace was left unguarded and abandoned for years.
When a former stableman at the palace died some years ago, it was found that he had stolen and kept about 300 pieces of prized imperial crockery.
But the palace's biggest draw remains Pu Yi, who became a global household name after the Oscar- winning film The Last Emperor, which was partly shot on the premises.
As Mr Wang said: 'We went to Italy and asked if they had heard of Changchun. They said no. We asked if they had heard of our palace. They said no. We asked if they had heard of Pu Yi, they said 'of course!'.'
Visitors to the palace can see how Pu Yi lived as a puppet ruler - shorn of real power but not lacking in the finer things of a regal life.
To keep him distracted, the Japanese built him gardens, an outdoor swimming pool, a horse-riding track, tennis court and even a small golf course as he was an avid golfer.
The complex comprises 10 buildings in a mix of European, Chinese and Japanese styles meant to keep Pu Yi comfortable and contented.
They have been painstakingly restored to their past splendour by curators who travelled across China and even visited Russia and Japan to interview some 100 witnesses, including former palace officials, guards and workers.
Some 3,000 old photographs of the compound were also acquired, allowing the museum to faithfully recreate the interior furnishings.
In the Tongde building where Pu Yi hosted foreign guests, curators realised that the main hall used to be lit by four huge copper-forged chandeliers, each weighing 120kg. They were believed to have been donated by Pu Yi to fund Japan's war efforts.
The museum sought out a famous chandelier maker in Guangdong to make replicas.
An obscure 'Manchukuo Architecture' magazine in a Dalian library was also uncovered. It contained a precious blueprint of the palace, allowing doors and rooms which were torn apart to be reconstructed.
But curators still had no idea how to rebuild the 11,000 sq m imperial gardens which Pu Yi and his concubines loved. Not a single photograph was found.
Then they had a stroke of luck. On a visit to Japan, the museum director found a book on Changchun during Japanese rule, with an introduction written by the man who designed the imperial gardens.
He was still alive and helped the palace restore the rockeries, fish ponds and the many cherry blossom trees which symbolised Manchu-Japanese friendship.
But despite the beauty and comfort of the royal residence, the original inhabitant was rarely happy. Pu Yi lived with the constant fear of Japanese espionage and assassination.
The depressed figurehead's health took a blow during those years, and he suffered severe constipation that forced him to spend a lot of time on the toilet.
That was quite possibly the only throne the tormented sovereign truly owned. A fitting irony, perhaps, for an illegitimate palace of a puppet emperor.