It's built on top of an ancient Indian burial ground. The high turnover rate among the extra devs hired for GalCiv2 was given a more-or-less official explaination in the GalCiv2 Post Mortem article, but the truth is that they were all murdered by the wrathful spirits of the long dead.
You can rest assured that everything you just read is true, because it's on the Internet. They don't just let people make stuff up, you know?