Academia - 400AF

Side Notes

The gate south of the Augusta Tower 200AF gate leads to the Yaschas Massif 100AF location. Beyond that you can also gain access to Sunleth Waterscape 400AF. Both require Wild Artefacts. Consider detouring to those or other Wild Artefact locations and possibly Serendipity before tackling the towers or before visiting Academia 4XXAF, which ends the episode.

Ghouls are plentiful in the Alley area and have Potent Orbs as their rare drop. To make farming these worth it you'll need the Item Collector ability, as you'll get hardly any CP or Gil for your efforts. Note that to do this after completing the location you will have to lock the gate, as the Ghouls disappear from the area after you leave Grand Avenue. As a much better option, the Bucaboos in the Archylte Steppe Stonestump Wastelands or Grave Ridge areas are the other worthwhile farming location and you'll get plenty of CP for your endeavors.

Also of note is the Fencer enemy. It's a good Ravager, but has a slim capture rate. There are also only 3 of these monsters in the entire game. You'll want to get the Monster Hunter Fragment Skill before hunting it. You'll need to repeatedly lock the location and fight the pair in the Alley.

Finally, there is an optional Cie'th battle with the Geiseric. It is located in the dead end north of where you crossed the Central Bridge, right by sphere 9 on the map. It is a difficult and lengthy battle if you tackle it on your first visit. However, it will fall much more easily if you return once your party is more developed. The reward for beating Geiseric is 1000 CP and 5000 Gil.