Yankee Hat is the name of a hill in Namadgi National Park in the South of the ACT. This walk is a return trip to some indigenous rock paintings.
You can park at the car park ("YH CARPARK" waypoint). The walk is a little under 3km each way, so allow 1 hour there and 1 hour back.
It would be tempting to take a short cut and walk straight across the swamp, but make sure you keep to the marked track. There is a visitors' book near the rock paintings.