Depending on who you're asking, there's either a lot on Kagatau or not much of anything. Indeed, there's no proof that anyone actually lives on this floating island at all, and there's been no efforts to settle there.
What Kagatau does have is a large jungle that hides a scattered collection of ruins. No one as of yet knows what civilization might have made them, though some researchers have recently been made aware of the ruins. The real problem is getting to them; the jungle is thick and is known to be home to a host of strange plants and animals not known of on the mainland. There's no telling how many would-be adventurers have lost their lives to the dangers here.