Augmented Crane Navigation System (ACNS) is designed to increase efficiency and safety in tower crane operations. Modern tower cranes can be more than 200 metres tall and operate in very complicated and complex environments. This implicates some significant impediments for crane operators, particularly with regard to seeing clearly at such distances and contending with blind spots – that is, angles that are obstructed by other construction equipment. To deal with this challenging environment, ACNS incorporates a 3D digital model of the construction site at hand and several high-precision GNSS receivers located throughout the crane. The GNSS receivers provide data on the rotations and movements of the load, which is then used for real-time navigation. Based on the navigation directions provided, the operator can safely deploy a load, even when the destination is not visible. ACNS is a forward-thinking concept for tower crane operations. Thanks to its user-friendly navigation tips, operations are possible even under very difficult conditions. ACNS also offers a basis for the complex automation of tower cranes.