So you can climb a 30-foot high wall?
Then when you climbing it you’re going to just jump down the other side?
Even a trained rock climber would have real problems climbing a wall with no handholds.
I am not saying it can’t be done, but most people that try will fail.
Particularly the most important criminals to keep out: Pregnant women and their anchor babies...
Climbing (and descending) a 30-ft wall (ladder of not), is a task 99% of the illegal scum could not manage alive...