Built for $70,000 in 1976, this underground Missouri concrete home survived a deadly F4 tornado; 50 years later, it remains almost invisible from the road, hidden beneath a hillside

Built in 1976 for $70,000, a remarkable underground home in Springfield, Missouri, was designed to blend into the hillside while providing strength and energy efficiency. Nearly 50 years later, the concrete residence remains largely hidden from view and has an extraordinary history, including surviving a devastating F4 tornado that struck the neighbourhood in 1990.