A couple spent 30 years renovating a nuclear missile silo into an underground castle.Now, the Kansas property is for sale for $3.2 million.These photos show inside the stunning property.Visit Business Insider's homepage for more stories.Kansas probably isn't where you'd first look if you're in the market for a castle, but you shouldn't miss this gem.Just 25 miles west of Topeka, this unique structure hides mostly underground. Ed and Dianna Peden bought this Cold War Atlas E nuclear missile silo and spent the last 33 years renovating it into an underground mansion and castle, which they rented out on Airbnb for years.Now, the Pedens are hoping to simplify and downsize, so they've enlisted friend and property manager Matthew Fulkerson to sell this unusual home. Fulkerson, who also got married on the property, has lived there and worked with the Pedens for the past 10 years.Owning this refurbished missile silo is a once in a lifetime opportunity, with a $3.2 million price for entry. These photos show the amazing renovation that took over three decades.SEE ALSO:2 Cold War-era nuclear missile silos sat abandoned for decades and just went on the sale in Arizona for $495,000 eachThe couple spent 33 years converting this Cold War-era nuclear missile silo into what they call a "subterra castle."The 18,000 underground mansion is "turn-key," meaning it can be bought and moved into with no additional work.The property is a great escape from the rest of the world, sitting on 34 secluded acres outside of Topeka, Kansas......with an 8-foot security fence surrounding the property, and two castle observation towers.It even has 47-ton blast doors.Underground entry tunnels are preserved from the property's days as a missile silo.Some parts of the property, like the old missile bay, still look like they did when the space was in use, while others have been totally renovated.The castle has several entertainment centers, and the furniture is available to purchase along with the property.Cozy decor and soft lighting could make you almost forget you're underground.These 150-foot tunnels lead to the original launch control desk......which still sits in its original spot.With stonework and some lights, even the industrial tunnels fit into the underground home's aesthetic.The Pedens say they've worked to make the space "cozy," no easy task for what is essentially a giant underground lair, but the property does have some homey charms.The 3,500 square foot great room even has a stage.In addition to the massive underground space, the property also has an above-ground living space.Also above-ground is a greenhouse powered by solar energy.The castle has two sets of four solar panels that contribute to the property's energy, along with a diesel generator.To top it all off, the castle even has a hot tub.The property is for sale by owner, and interested buyers can contact Matthew Fulkerson at firstname.lastname@example.org. Click here to read full news..