by louper
You cannot use Activity IV until your guard goes around the entire rampart (20 spaces). If proof is needed, my version of the rules states:"Once your guard reaches or passes a city gate, you have access to the outdoor activity outside that gate for the rest of the game." (Page 2)
If you believe that you can use Activity IV immediately, then you must believe that the guard has either reached or passed the gate, based on the above statement. He clearly has not passed it, so he must have reached it.
If so, consider the Important Note from page 3:
"When your guard first reaches the gate at the top of the board, you must place it on the Level IV activity associated with it... You may still use Action 7 to put cubes on the 4 outdoor activities."
Since you have concluded your guard has reached, not passed, Activity IV, immediately place him on the Level IV activity card, based on the above note. Now, you can no longer move him, as stated, but you can put cubes on all 4 activity cards.
So, in essence, if you assume that he's reached Activity IV, you're assuming he's done moving, has reached them all, and everyone can access all the activities from the beginning of the game. Might as well throw away the guard pieces - you won't be needing them.
That, as Neil said, "would be just silly."
"Oh no, I'm so sorry, it's 'The Moops.' The correct answer is 'The Moops.'"