You took the witches advice, and followed the path that would take you, and the prince frog to the tower, which wasn't that hard to do since you just had to make it through a dark forest without getting hurt, and a meadow full of grass. You then see the path lead up a giant hill, that had the smell of ash in the air.
You get frightened noticing what might come, and as you finished climbing the front hill side, you found a bridge on top of a moat filled with magma, that lead to the exact tower the witch mentioned before. You cross the bridge, without alerting the dragon that might be guarding it, because you knew that he might suspect you if you made any loud noises which would startle a wild animal such as a dragon that could breathe fire. Without any problems, you made it through the bridge, and entered the tower.