If you've ever wanted to own your own decommissioned missile silo or other missile base property, NOW is the time!
This is some cool ass stuff. Some of the nifty features: half-mile long tunnels, stairs and ladders galore, thousands of feet of floor space (one had 15,000 sq ft!), that great concrete look, giant diesel engines and turbines, old computer thingys with switches (what are those, grandpa?), multi-ton blast doors, and if an area is flooded you can use it for scuba diving!
And since most of it is all underground, you can probably throw up a bunch of solar panels on top, maybe even a wind mill/turbine, and generate your own electricity. Neato!