The locked cave you speak about is called the Dotted Hole. To get inside and retrieve the Sapphire, you need to CUT the door.
Some Pokemon that can learn CUT are:
Bulbasaur and the following evolutions: Ivysaur and Venusaur
Charmander and the following evolutions: Charmeleon and Charizard
Beedrill
Rattata and its evolution Raticate
Sandshrew and its evolution Sandslash
Farfetch'd
Nidoran male and female and all their evolutions: Nidorina, Nidorino, Nidoqueen and Nidoking
Oddish and its evolutions: Gloom, Vileplume and Bellossom
Krabby and Kingler
Lickitung
Tangela
Meowth and Persian
Paras and Parasect
Tentacool and Tentacruel
Diglett and Dugtrio
Bellsprout and evolutions: Weepinbell and Victreebel
Pinsir
Kabutops
Scyther and Scizor
Mew
Aerodactyl
Entei
Suicune
Raikou
Tyranitar
Skarmory
Gligar
Steelix
Heracross
Espeon and Umbreon
Sunkern and Sunflora
Aipom
Sentret and Furret
Chikorita and its evolutions: Bayleef and Meganium
Totodile and its evolutions: Croconaw and Feraligatr
Cyndaquil and its evolutions: Quilava and Typhlosion
Celebi
Torchic and its evolutions: Combusken and Blaziken
Zigzagoon and Linoone
Nincada and its evolutions Ninjask and Shedinja
Roselia
Aron and its evolutions: Lairon and Aggron
Treecko and its evolutions: Grovyle and Sceptile
Nuzleaf and Shiftry
Slakoth and its evolutions: Vigoroth and Slaking
Sableye
Too tired to keep typing but that should get you started somewhat!
Icefall Cave is located at four Island.
use cut
Island 6 near the edge
I obtained a Delibird in Fire Red in Icefall Cave on Island 4.
it is in ice fall cave on four island but you need to find it somewhere in the cave
You cannot find Sneasel in Fire red it is only found in leaf green in the ice cave on Four Island. You can only find Delibird in fire red.
In myth Medusa lived in a cave on the island of Cisthene in the Red Sea. In reality she in your freaking head and if you see her you have schizophrenia and will be locked in a padded room for the rest of your life.
On island one, there is a cave with a ruby and a full set of braille alphabet.
Most strong Pokemon can be found also at seven island
in the cave
It's in Mt Ember inside a cave Rocket Grunts opened for you.
In the seafoam island just south east of fuchsia city and keep going on your SURFING Pokemon and you should end up at the entrance of a cave it is in that cave