The 15 story "Ark Hotel" in Changsha, China was built in just 6 days!
It was started on Saturday. Finished by Friday!
In case your questioning it's structural integrity, it's supposed to be a level 9 Earthquake-resistant structure.
PS--Our own rebuilding of the One World Trade Center won't be finished till March (2013). Some 8 years after it's final design was formally approved in June of 2005.
And almost 5 years after work on it's concrete core began in 2008!