This place couldn't be more different to Magmoor below. Go through the door ahead to find your path blocked by frozen ice, so blow it open with a missile. Two more ice blockages block the tunnel ahead, blow them open to reach the exit. Go through the door to reach the Phendrana Shorelines - your first real glimpse of this frozen place. There's a lot to see in this area, so we'll concentrate on our objectives (feel free to look around though).
Scan the various creatures in this area, then go over to the metal grating covering a small tunnel on the left. Blow it open with a missile and go inside. Shoot the Crystallite inside with a missile and crawl through the small gap with the Morph Ball. Scan the console on the wall to unlock the door on the cliff directly above. Climb back up to the edge of the lake and go over to the side where you'll find a Save Room hidden.
After saving your game, climb up the cliff side back in the Phendrana Shorelines area. Once at the top you'll be able to jump across to reach the door that you unlocked earlier. The next tunnel has another ice blockage, blow it open then scan the purple floating creature to reveal it as a Scatter Bombu. You'll need to use the Morph Ball to avoid the electrical conduits flying out of its body. Roll past and head through the tunnel to find a door behind another Scatter Bombu.
Go through to find yourself in an area full of ruined Chozo structures. Around the corner you'll confront two Baby Sheegoths, you'll need to pound them in the back to finish each one off, just try not to take too much damage from them. If you get caught by their ice breath and become frozen, tap A or B to break out. Go over to the wall ahead once they're gone and climb up.
Climb around the tops of the ruined buildings to eventually reach the next door at the top of a small cliff. Go inside to find yourself in a long cave filled with Ice Burrowers. Scan one of them before proceeding, then finish them all off before leaving. Through the next door you'll find yourself back in the Phendrana Shorelines but high up on a cliff (don't fall off). Go up the snow ramp on the left to find another door and head through.
Cross the next room while dodging the three Pulse Bombus floating around (if you stand near one of them as they drop electrical bombs, Samus' visor will light up and you'll catch glimpses of her face reflected in the visor - pretty neat!). The next area contains more ruined Chozo buildings, as well as two more Baby Sheegoths.
Up to the right of the entrance you'll find an entrance leading into a ruined building, scan the shimmering wall above for the Cipher Chozo Lore entry. Go back outside and finish off the two Baby Sheegoths before proceeding.
Go past the area where they first sat, then turn right to find a passage leading down to a door. Blow off the Blast Shield and head inside. Roll through the next corridor while dodging the two Scatter Bombus, through the next door you'll find yourself in the Phendrana Canyon.
This giant area has a few tidbits waiting for you. Drop off the cliff ahead to land on the large bridge below. Turn around to find a shimmering wall hidden behind a stack of crates. Scan it to record The Turned/Entrusted One Chozo Lore entry. Jump off the end of the bridge and finish off the Baby Sheegoth below.
Walk up the snowy ramp ahead and scan the console/statue there to realign all the floating platforms hovering over the ice half-pipe ahead. Now it's time to pay off all your travelling since finding the Varia Suit. Use the platforms as stepping stones to reach a large tower at the far end of the canyon. Inside you'll find none other than the Boost Ball!
You'll have to utilize this new ability to leave this area. Drop down into the half-pipe and roll over to the cliff edge the camera will point out to you. Charge up the Boost Ball with B to start rolling around the edges. The trick to gaining maximum height and thrust with this is to hold B and release it just when Samus begins to roll up one of the sides of the half-pipe.
While she's in the air begin charging it again to release it when she begins to rise up the other side of the pipe. This way you'll gain enough altitude to land on the cliff above. Climb up the cliff to eventually reach the door. We've now done all we can in Phendrana for now, so it's time to return back to the Tallon Overworld to find some more nifty items.