you get the HM strength
Use the HM move Strength.
Move all the boulders into the holes to beat tanoby chamber.
You can use the move strength in Pokémon to move boulders. You can use strength in FireRed after getting the rainbow badge.
They are located at the Tanoby Ruins in Seven Island. first you have to move 7 boulders on the main island before the appear
i think the ruins have unown in them; when you move the boulders on six or seven island into the holes. it will say there was an earthquake, and then you can go back and find unown.
Use Strength to move the boulders onto the switches, keep doing that on each floor to reach the next until your finally outta there.
HM "Strength" is used to move boulders.
First, you have to get the HM strength, then teach it to and a Pokemon and you can move boulders.
Push them in a way so that you can go through, if your doing the tanoby key puzzle the last boulders you want to push is the bottom boulders.
You might move boulders off of the seafloor cavern into a ship in order to examine the boulders. Often, this is accomplished using buoys that float the boulders from the seafloor to the ship.
To move the boulders and clear a path. If there are two types of boulders in your version the boulders with cracks need to have rock smash used on them instead of strenght.
You have to go through the Safari Zone, towards the place where you get surf, and find the Warden's teeth. Take him his teeth and he'll give you HM 04, Strength. This HM allows you to move boulders, if you have the correct Badge.