Up and over!

You decide it would be best to scale the wall. That's only natural, since you were a born climber. When you were young, your nickname was "Monkey," and for good reason. The only real issue is being seen, but luckily for you, it's night-time, and the light of the moon is barely enough to climb by.

With no time to waste, you quickly scramble up the lower sections of the wall with ease. You falter some in the middle of the climb, but quickly regain your footing and continue your upwards journey. Upon reaching the top, you check for a guard, then climb over the parapets and onto the wall.

From here, there are a number of ways you could continue further in... there are several open windows, though the contents of the rooms on the other side are impossible to guess from here. Alternatively, you could climb down just as you climbed up, but this side is better lit... or you could do something else entirely.