Drúadan Forest

Well, yes, he would have done if Théoden had taken that road, but he didn't.

He went through the Druadan forest instead, a forest usually avoided by the Rohirrim and Gondorians, as they believed it to be haunted.

but this time they were shown through the secret ways of the forest by the wozes the people who lived there and had long been persecuted and hunted by the outside world theodine promised and aragorn later delivered independence and protection for that people going forward In terms of this battle, it meant that the Rohirrim arrived on time, didn't have to face orcs en route, and their arrival surprised the Witch-King, who hadn't expected them.

The Rohirrim's first charge did immense damage to the Haradrim cavalry, clearing the northern part of the battlefield of the enemy.