The second Prototype 2 sub-zone you will explore, during the game, is Oakhurst.
If you travel south from Fairview, in the Yellow Zone, you will reach Oakhurst.
Oakhurst is a sub-zone larger than Fairview; however it includes only five hidden Blackboxes.
There arent any Lairs and Field Ops in Oakhurst.
Collecting all Prototype 2 Oakhurst Blackboxes is, however, an important step, because the reward you will receive is a new offensive mutation for Heller.
Three Blackboxes are in the south-western part, one in the northern Oakhurst, and one in the eastern Oakhurst, near the docks.
Below, you can find the coordinates for each Prototype 2 Blackbox in Oakhurst which reveal their exact locations.
After you collect all of them, travel south to enter the next sub-zone, Linden Park.
Oakhurst Blackboxes Coordinates
Blackbox #5: 464, 1145
Blackbox #6: 312, 1191
Blackbox #7: 224, 1274
Blackbox #8: 234, 1346
Blackbox #9: 122, 1229