Second World ABP and EXP Grinding Location
The best location for players to grind for both EXP and ABP on World 2 is in Castle Bal's basement. You'll spend some time here as you're going through World 2 for Galuf's story events and you'll also be barred entry from the castle for a little while too while on World 2. Then finally once the worlds merge you'll be able to come here anytime you want as well as acquire Odin who is found in the northern room.
Once you're inside the castle you'll find the Objet d'Art (Rock Statue on PS1) enemies in the eastern most portion. In the room just above the Castle's Basement you'll find a Save Circle which makes a great location to rest up after you grind for a little. Primarily what makes this location so good is the amount of ABP that these enemies give. Since these enemies give EXP too, and a decent amount of it at that - this location serves to benefit you whether or not you're looking for ABP or EXP.
Ps1: Rock Statue
GBA/ioS: Objet d'Art
These enemies come in groups of 2 or 5 and they cast Stone fairly regularly before they run out of MP, which happens quickly for them. That means if you're the type of person who likes to turn Frame Limiting off and spam auto attack to defeat enemies you won't have too much luck doing that here. It's not uncommon to have half your Party turned to Stone in one round.
Since these enemies cast Stone so much you're definitely going to want to stock up on Softs (or Gold Needles; depending on your translation) before you decide to grind here. You're going to definitely be using at least one per battle. One thing to keep in mind about these items is you can also use them on the enemies you're fighting. Throw a Soft at one of the Objet d'Arts and you'll instantly defeat them.
Battle against 2 Objet d'Art yields: 1014 GP, 50 EXP, 4 ABP
Battle against 5 Objet d'Art yields: 2535 GP, 125 EXP, 8 ABP
That's about all there is to this location. I highly recommend this location as it's a great spot to level up your Jobs while also getting EXP. From here on out the game will get much harder if you're under leveled or using poor job combinations. At the same time, you need to use poor Job combinations sometimes in order to make your Freelancer Jobs better. I use this location to level up at least two Jobs per character before moving onto World 3. With all the grinding I typically do in Jachol during World 1 this gives me 4 or 5 Jobs Mastered in total.