Where is this place you talking about? Well to get there from Edgevill bank you take this DFO Gold route. Once you go down the hole, in level 6 wildernesses you will be here.
For each Dragon there is a safe spot. Here are the locations of the dragons, and the safe spots. Once you are finished the load, than just simply go back to the bank and bank, than repeat the process.
Extra Information about this creatures and Guide - When you are at this particular place for Green dragons I recommend being a higher level for a couple of reasons:
-It is a multi person area (anyone can attack your dragon)
-There are four level 83 Baby Black Dragons that attack people
Drops that you should pick up for greater profit (apart from the Green dragon-hide and Dragon bone)
-Water rune (ONLY if you have over 75, so 150 minimum)
-Loop half of key
-Adamant helmet (Than high alchemy it if you have over 55 magic)
-Grimmy Dwarf Weed
The reason I use combat potion is because it boost up my attack and strength, and I use one zip because I can drop the vial and use the space for the bone/Dragon-hide.