If you are looking for the lighthouse, head north, and take the NW gate (behind the King Crab).
For the mines, boost your perception, fireball everything in front of you, throw crates or barrels along your path...
You can use potions, skills, equipment bonuses or levelling to boost perception, and there is a talent that will help with perception specifically for traps. You could also quick save/load to proceed by trial and error.