There are three towers. Two are on the main road and the last one branches off to the side. The quest arrow only points out the nearest one, so depending on where you are it can be difficult to find the last tower.
I'm quoting someone from a long ago thread on Wizard101 Central.
"The first scout tower is across the field where the dogo is (near the beginning of the path). The second tower is taking a right after the first tower and continuing forward. The last tower is in the area where Lili Ma is standing."