10. Nekoma: North Dakota
This is not a long lost pyramid of the Amerindian nations. It’s what remains of a once state-of-the-art facility, an anti-ballistic missile (ABM) defense system from the Cold War, part of the U.S. Army’s Safeguard Program. They designed this facility to primarily detect missiles from the Chinese as the Soviets had too many missiles for the system to track. It would fail under such an attack. The idea was to build more of these facilities all over the U.S., but the prospect of money spent on ABMs over ICBMs went the way of more missiles instead. Both accomplished the end goal of financially bleeding the Soviets, but the ICBM would remain an asset after the Cold War.