Runescape is widely known for its' vast continent and different dimensions, pieces and bits of other worlds all blended so well together. The one thing that I miss is a vast underwater continent, like the giant oyster area but then bigger, bolder and better. Since it would open up so much content for existing content//skills. For e.g. mining//smithing new kinds of coral armours, wootcutting//herblore algae that can be harvested and made into potions, invention could be used to make diving gear like an underwater breather//diving aparatus, agility could be used to explore underwater caves, hunting could be used to trap fish//underwater creatures... It could be maybe implemented alongside the third elite dungeon.