The only way to reach Mineral Springs is by going through the Granite Citadel. First you will need to leave east to Tasca's Demise. From there you will continue east, then turn north east. You will find the exit to Mineral Springs. From here there are two possible routes you can follow, as shown on the map to Nicholas the Traveler. The easiest path is to turn right after entering the Mineral springs and follow that path. It will bring you to him on the eastern part of Mineral Springs. There are several groups of Avicara along the path, including bosses. Something to prevent Knockdown is very helpful.