This very architectural hat uses a herringbone stitch pattern for the main body, and smaller than usual needles for a bulky yarn, to create a dense weave that (so I hear!) keeps out the wind.

The Large fits heads that are 23 - 24 inches in diameter, the small fits a smaller adult head (21 - 22 inches). It would probably fit the head of an older child.

When knitting the Large, I have run out of yarn a few very short rows before the tip of the hat, and have used another color for the last bit. You could decide to use a contrasting color for the 2 rows at the ridge, which looks nice and would most likely leave enough yardage for the tip.