Ice Ruins East

Ice Ruins East is a room in the Phendrana Drifts region of Metroid Prime.

Without Spider Ball

Perform a HBJ at the base of the Spider track to enter the tunnel with the Missile.

Make your way up to the door leading to Plaza Walkway. Face the door and turn about 110 degrees so you see a pillar nearly right in front of you. Jump on this pillar. Now turn a bit more to the left and you should see a lone brick sticking out of the wall. Do a L-Jump towards it. Now turn and face the door leading to Plaza Walkway again. Turn about 30 degrees to the right and you'll see a small ledge that isn't covered in snow, wedged in between two rocks. Do a lengthy L-Jump to this. Now jump backwards enough to clear the overhang, then use your second jump to jump to the right and over the wall.
It is also possible to do this secret world without Space Jump with an HBJ.
This was secret world #4 in the original numbering scheme.