I once lived in Toronto and from my balcony I could see the Four Seasons hotel under construction. Eventually it would be around 50 stories tall, and it seemed to increase by about a floor per week. Not bad, I thought.
But China seems to think this is rather sluggish. It has just built a 57 story building in 19 days. (Though a lot of it is modular construction that was made in a factory and assembled on sight.)
Watch this video and marvel, and imagine going on holiday for a couple of weeks and returning to find a skyscraper where there used to be a minor construction site.