Your airport starts at Level 1 and can reach Level 3, unlocking larger terminals and specialized buildings.
Unlike standard ploppable buildings, the Airports DLC requires you to define a specific zone before building. codex-cities-skylines-airports-iso
: The primary way to level up is by increasing the total number of passengers processed. Your airport starts at Level 1 and can
If you're looking for help with (specifically referring to the DLC release often associated with the CODEX/ISO scene), 1. Getting Started: The Airport Area making it suitable for runways.
: Painting an area automatically flattens the terrain, making it suitable for runways.