The Jump skill states that:
The Survivor can use this Skill once during each Activation. The Survivor spends one Action: He moves two Zones into a Zone to which he has Line of Sight. Movement related Skills (like +1 Zone per Move Action or Slippery) are ignored, but Movement penalties (like having Zombies in the starting Zone) apply. Ignore everything in the intervening Zone.
An interesting tactic is to be able to jump into/out of towers. Is this legal?