The creators made bending a natural extension of consistent limitations and rules of the world. Everything in Avatar's world, whether it be clothing, culture or infrastructure, is influenced by bending. The City of Omashu uses a complex system of gravity and earthbending to transport supplies. The Water Tribes were a naval superpower: their buildings are made of ice and used waterbending as mechanisms for their walls and gates. Airbenders built temples atop high mountains and cliffs that could only be easily reached by Airbending and they have a hermetic ideology to reflect this isolation. The Fire Nation were the first to industrialize due to their ability to generate power and master metallurgy with their bending of fire and lightning.