Find out how to get Regice, Regirock and Registeel, the 3 Legendary Golems!
Where to make them appear and how to catch them
First, head to the edge of Route 221. There you will find Ramanas Park. That is where you can meet and catch the 3 Golems. To get in, make sure you have: beaten the Pokémon League, unlocked the National Pokédex and obtained the HM Surf
If you have done all that, you will have access! Next, you will need to get slates. They are exchanged for small Strange Shards or a large Strange Shard. You can find these shards by mining in the Grand Underground.
One slate, 3 Golems
In Ramanas Park you will find several caves. Each one requires a specific type of slate to summon a Legendary Pokémon. For the 3 Golems, you need to go to the cave called the Guides Chamber with at least one Guides Slate. Once you have at least one, you can place it in the Guides Chamber and make one of the 3 Golems appear at random.
Regice, the ice golem
Regice Shiny Regice
Regice instantly freezes anyone who approaches it with icy air that can reach -200 °C.
Type : 
Weaknesses :
Height : 1,8 m
Weight : 175,0 kg
Gender : unknown
Category : Iceberg Pokémon
Ability : Clear Body
Regirock, the rock golem
Regirock Shiny Regirock
Its body is made entirely of stone. If any part of it crumbles, it repairs itself by sticking rocks onto it.
Type :
Weaknesses : 
Height : 1,7 m
Weight : 230,0 kg
Gender : unknown
Category : Rock Peak Pokémon
Ability : Clear Body
Registeel, the iron golem
Registeel Shiny Registeel
It is made of a mysterious material that is harder than any metal, yet flexible enough to stretch or shrink.
Type :
Weaknesses :
Height : 1,9 m
Weight : 205,0 kg
Gender : unknown
Category : Iron Pokémon
Ability : Clear Body
Did you knock them out?
If you knock out one of the 3 Golems, or even all 3, you can make them reappear, but you will need a slate again. Once one is caught, you can no longer make it reappear, because it then appears on its monument.
On your way out, an NPC will also give you a statue of the Golem, if you have just caught it.
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Credits to Poképedia for the sprites.
