Attack points are very important on any leg – they are the large feature you navigate to using rough technique before starting into fine orienteering. For example, you might use a large vegetation boundary, a path junction, or a hill top as your attack point before going on to find a knoll or a boulder.
On the leg above, 4-5, a possible route would be to come up to the path, follow it West until the vegetation boundary, which you use as your attack point. Then move into the forest and follow the boundary to the control site.
On this leg (North-South), use the hill as an attack point – aim for the hilltop, then once you are close you will see the ruined wall, which can be followed into the control, on a boulder.
Aiming for a clear attack point means that on every leg, you know exactly what you are doing – you don’t just run blindly and hope, but you navigate to a certain point on your route. On a longer leg, multiple attack points are useful – you pick them up on your way along the leg, making sure you know where you are.