The Old Summer Palace in Beijing (not to be confused with the New Summer Palace still standing) was destroyed in the Opium War of 1860, and was considered the pinnacle of Chinese architecture and design - the world's largest palace, made up of myriad pavilions, on islands in myriad lakes, in the world's largest gardens, covering 4.5x the area of the Forbidden City. It was so large it took 4,500 troops 3 days and nights to burn and loot, parts of its stolen treasures are now in 47 different museums and galleries round the world.
The ruins have been kept as a lesson to history BUT new controversy surrounds the rebuilding of it in Hangzhou, a city 1000km distant.
The first phase alone has costed $4.6 billion, even with China's cheap labour. If considered one building it would be the world's 4th most expensive even before finishing.
The custodians of the Old Summer Palace site are now threatening to sue over any infringement of intellectual property.