In an undisclosed location in Kansas, a former Atlas class missile silo has been turned into an underground, 15-floor condo building. Building amenities include nuclear, biological and chemical air filtration; hydroponic food production areas; and a workout facility complete with pool and spa. The units themselves include a biometric key system, a simulated window that reflects time of day and in-unit washer and dryer. The silo is now under construction with units on the market ranging from $1.5 million for a 920-square-foot half-floor space to $4.5 million for a two-level “penthouse.” Credit: survivalcondo.com.