SleepDeprivation

My clue led me to 21 24 North 17 54 East. I used the Tip.It locator and it shows the Lesser Cage. I checked RuneHq and it said in the Lesser Cage... I've dug all around the outside and in the inside near the location. Where exactly do you dig in the cage? Theres no specific answer and its just not working. I have my spade, map, compass, and sextant so thats not the problem. Please help. Thanks.