This might work in a universe with spherical cows but they seem to hand wave away all human elements. My eyes rolled a loop in my head when they advised an urb

This might work in a universe with spherical cows but they seem to hand wave away all human elements. My eyes rolled a loop in my head when they advised an urban location. That's a great way to ensure it gets demolished when a marginally better use for the land comes along. If it were me I'd just build some monstrosity of a palace in somewhere that nobody wants such a thing and I'd build it out of stuff that's highly inefficient to repurpose, not steel beams. The best way to keep something around is to make its continued use better than any other option so that people take care of it and give it the capacity to withstand a couple generations of neglect without falling in on itself. A castle (metaphorical or literal) on some cheap land along the highway in North Dakota should suffice.