It's north of Hia Valley
you have to take a detour on ice lake.
2 words for u ICE LAKE
Vien forest, union road, and the crystal lake.
If you have the empolean just dodge the ice cicles.
you go to the old ladies house then go to the right and catch an Empoleon and ride it and you are there
Once you get past the Icy Lake on the Empoleon, the castle will be right there. The lake is north of Hia Valley.
If you're asking about the blue crystal in Pokemon Ranger Shadows of Almia, then it's at the top of Almia Castle. To get there you surf with a Floatzel through Crysta Cave then go through Hia Valley then surf through the icy lake and then go all the way to the top of the castle and fight Lucario and then you'll have it.
IN the almia castle up of ice lake
In "Pokémon Ranger: Shadows of Almia," you can locate Vaporeon in the Almia Castle and in the Altru Tower. You can locate Jolteon in the Habura Desert, you can find Flareon in the Volcano Cave, Espeon can be found in the Hippowdon Temple, Umbreon can be found in the Chroma Ruins, Leafeon can be found in the Vien Forest and Glaceon can be found in the Ice Lake.
It is past the ice lake that you must get through with an Empoleon.
go to Almia Castle, then dont go in. Go across to the right. Then travel a little down the ice lake, then up to that place that you should see. Glacion is there.
you can catch a jigglypuff in the cave on the way to almia castle, go south from the rangers union and get on a Floatzel and take the nearest lake you will find it in Crysta Cave on the way to hia valley.