One of the longest underwater vehicular tunnels in the world, it was designed as the masterpiece of Clifford M. Holland’s career and was decades in the making, Even today, it serves New York and New Jersey—though as thousands pass through this tunnel every day, it is easy to overlook just how incredible the ingenious engineering behind the tunnel’s ventilation system truly is. Today, we’ll be taking a look into the story of the Holland Tunnel—a truly crowning achievement of its time.