Edoras
Edoras was at the point where the Snowbourne emerged from the mountains and turned east to join the Entwash. Four roads met there: the Great West Road to Minas Tirith, the path Eomer and his Riders had taken to the Entwade, the road to the Fords of Isen, and the road south up the valley to Dunharrow. (The King of the Golden Hall; Bk 2).
When Gandalf and the others set off again with Theoden and his men, they took the road leading north-west along the foothills of the White Mountains. It was more than 40 leagues (120 miles) direct, or say 135 miles by the road.