Climbing up, in to a wall

[JP_Finn]

Found an odd one: can climb to inside a wall.
Setup needs a climbable  rock wall upon which a log wall is built. Climbing that slope will position the character in/on the wall.
Not sure if NPC could climb up and bypass a wall. Neither have I've had a chance to test if enemy arrows would hit the wall or the character.
see pics VV