This is absolutely amazing - this monument has been around for 30 years and i just heard about it. Someone, somewhere is:
1) playing an expensive practical joke
2) preparing for the possible collapse of civilization
3) instigating the collapse of civilization
4) what is your theory?

It had to have cost a million dollars in 1980 dollars (about 3-4 million in today's dollars). They seem to have taken everything into account (except that box in the back of the garage - or did they plan for that too?).