Dear EvilEngineer; Could I build a solid gold castle?

After a long and lucrative career in real estate, I am ready to put my wealth to good use. I would like to build myself a castle from gold, à la El Dorado. When I say gold, I should specify that I mean solid gold, not gold leaf. I didn't spend 50 years exploiting my workers, squashing my competition beneath falling pianos, fibbing to regulators, and siphoning off my employees’ pension to live out my retirement like a poseur in a shiny concrete chateau.