Dan-Gun is an ITF/Chang'Hon pattern. It has 21 movements and the diagram is a capital I. It's named after the holy Dan-Gun, the legendary founder of Korea in the year 2,333 BC.
This pattern is learned at gold/yellow belt. An interesting fact is that all the punches are high-section in this pattern, meaning eye-level. An easy way to remember that the punches are aimed upward, is to remember that that you are punching toward the sun, the color of your belt.