A few minutes later, Jonathon led the way to the entrance. The building was an old jet hangar, built from thickly corrugated sheet metal covered with peeling white paint. It was huge, stretching up at least ten stories, and five times as long as it was tall. Facing them as they approached were the massive double doors of the original hangar, seven or more stories tall themselves, built to accommodate the giant jumbo jets of the last century.