the island cave is on route 105.
It is on dewford island.
After you beat the Pokemon league, go to One Island. Go to the base of Mt. Ember, where you saw the 2 Rockets. They should now be standing in front of the opening of a cave. Beat them, go in, and go to the end of the cave, where you'll find the ruby.
You probably mean southern island not southern cave because southern cave does not exist, southern island is an island you can only venture to on emerald and not ruby because of the eon ticket.
Regice is on Island Cave on Route 105.
Try talking to celio at the one island Pokemon center.
Island cave, Desert ruins, Sky Pillar, Any route, Cave of Origin.
You Get the ruby from the cave and bring it to the Pokemon center on 1 island. He's standing to the right when you first walk in. The ruby is in 1 island at the mountain, you'll see two Rocket members guarding the entrance. I think you just battle them to get in, then its at the end of the cave.
On island one, there is a cave with a ruby and a full set of braille alphabet.
there is no diglett cave in Pokemon ruby only in leaf green and fire red
First you must defeat team magma at an underwater cave near the island where Ever Grand city is located.
Pokemon diamond/pearl-trade PLATNUM-mt.cornet Pokemon emerald/sapphire/ruby-island cave-avalble by surfing
The legendary pokemon are located in: Cave of Origin, Sky Pillar, Desert Tomb, Island Tomb, Ancient Tomb.