I'm sure Newgrange was built by slaves. Wasn't slavery universal back in them days?Well fuck it, The Great Wall or something, there must be some shit somewhere we can blow up
The pyramids story seems a bit implausible - you have a society with slavery, and wanna build a gigantic stone structure. Why wouldn't you use slaves? You'd probably need skilled stonemasons too, and you might bury those guys properly, but when slaves died you'd just sling em in the river with the crocodiles