Juna, a great snake lives in the depths of the caves under Lumbridge. Ordered there by Guthix himself, she to this day guards a sacred cave where Guthix came to cry after seeing the damage done by the God Wars in the Third Age. As he wept, the caves started to with him, and as they continue on now.
Juna won't let any adventurers into the cave without first proving themselves in the quest, Tears of Guthix. After the quest, you must wait one week gain at least 1 Quest Point or 100,000 EXP before you can tell her a story and are able enter the cave again.
Note: You must have a light source to go through Lumbridge Caves!
From Lumbridge Castle's Basement, go through the whole in the wall, then continue south, ignoring the goblin maze. Go into the Lumbridge Slayer Caves, and continue straight south. Jump onto the stepping stones (Careful! If you fail and have an open light source, it WILL put it out!) Enter the Cave Entrance, and head east, down the slope, and talk to Juna.
Once you're in the cave, your goal is to collect blue tears, and avoid the green. Your time limit in the cave is based on the number of quest points you have, and you get experience in your lowest skill when your time runs out.