When it comes to buying a house, you don’t really have a whole lot of time to poke around every nook and cranny. Even if you pay for a home inspection, you can often still find unwelcome surprises left behind by the previous owners after they move out. Sometimes, however, those surprises can turn out to give your new home even more value. That’s exactly happened to this man when he stumbled on an amazing structure hiding underground in his backyard. Just wait until you see what he found! After discovering and looking at the original plans to his house, this man found something peculiar in his backyard that he had never noticed all the while that he was living in that home. He was excited to see what it was about.