Its a little more than 1/2 mile walk to get to the parking lot if you just go up the paved park road from the entrance. That includes an uphill. But, before you reach the lot (and top of hill), you can take a detour and go to the right and look out over the cliff at the airport and planes parked below. Maybe with some luck one will land or take off.
If you continue up into the lot and stay along the left edge, you will see the tunnels about 1/2 way up the lot. Those are kind of neat for kids. You will have done 3/4 mile already. If you wander around the trails in the woods to the East (the tunnel side) there are some old cages in that vicinity. Kind of hard to remember the exact turns.
If you were to stay in the lot and walk along the tunnel side to the top and then turn left (paved), then turn right (woods road), there is an old choo-choo track up that way. That might be a little beyond the stamina of the 4 year old.
If you know your way to the base of Otter Slide trail, there is an old Otter slide exhibit at the junction of Warthog and Otter Slide.
Hope that helps a little!
damn, so they removed the entrance way.....can anyone advise if anything else was removed yet? Is the place suitable to take the family hiking to point out the odd little items still about and to "search" for released zoo animals? Have far in do you have to hike to see the old exhibit locations? My youngest is 4 so after a mile or so, I'm sure he'll start dragging.....thx