Also, there is a quest where you are required to search for "Molar Fragments." It's listed in the Quest Goal box as "Strange Medicine Merchant" or something. The animals you need to kill are right in the area of the Escaton Ruins, if I had to give a # that is currently on the map, go for 12 or 13. If that isn't exactly correct, look around in that area, and you'll find it. I stumbled upon by accident, lol.
Alright. Now, having actually participated a few times in the quests inside Argilla Ruins, I know how difficult in can be. Hopefully, this map, provided by LyquidFyre should help out a lot. The entrance to the ruins is at the bottom of the map where you see the numbers 2 1 2 and a green dot. The last part of the map going to Knight -- you'll enter a room with a pillar, go around the pillar and down the ramp that's there and you'll see a portal. Go through that portal and you'll be in the final chamber.