Where is the blue key?

Hint 1 of 4:

The blue key is across the chasm (which you get to if you turn right at the
fork).

Hint 2 of 4:

Once you jump across, continue on and look for a waterfall.

Hint 3 of 4:

Go behind the waterfall and look for a narrow stairway.

Hint 4 of 4:

Keep going and eventually you'll find the blue card on an ice block.