You can only obtain ice in the Winter season.

When you carry ice in your inventory, it will melt instead of rotting any ingredients at midnight. When ice melts, it becomes the ingredient Renowned Water.

Ice will only melt up to 5 stacks a day. So you can preserve ingredients year round, if you manage to stockpile about 50 ice before Winter 3 ends and Spring 1 starts.

From what I have tested, not all mining spots in a stage will contain ice. I will only list the mining spots that do contain ice.

Mining spots take a few days to respawn, so it would be best to try and collect from as many points as possible as soon as Winter starts, so you can grab them again when Winter ends.

Proceed through the upper path of the stage crossing the two whirlpools. Cross the water bubble, and fall down the third whirlpool you see.

Proceed right from there and take the fall down the shaft, but do not use the shortcut on the false wall to the right, go to the left past the bubbles with the spike floor, and continue left until you see bird and clam enemies.
At the left of them there will be a pit. Go down carefully, there is a whirlpool but the mining spot is just before it.

Before the whirlpool inside the pit, there's an enclosure with a mining spot on the right.



You cannot enter this stage directly, so run through Radiant River Gorge 1. The last screen before transitioning to Gorge 2 requires you to defeat all enemies on screen.
Upon entering Gorge 2, run forward and go on the lower path.

There will be a mining spot near the wall. Despite the normal ore graphics, this mining spot contains ice. There are deer, turtle, fish, and clam enemies in this enclosure, and a small ! gathering spot.

Return to the upper path and proceed through the stage. There will be a mining spot behind a water bubble moving up and down.

You can exit back to world map.

You cannot enter this stage directly, so enter from Radiant River Gorge 3 and defeat Yellow Claws.
Upon entering Gorge 4, proceed throughout the stage, just past the floor of spikes there will be a mining spot to the right in a small enclosure

Exit the enclosure and go up past the cliff to proceed through the stage. When you see the whirlpool that drops you into the large pit with enemies, go down and there will be a mining spot to the left of the enemies at ground level.

Defeat all the enemies in that location to continue moving right, and there will be a mining spot at the wall on the right.

Proceed to Radiant River Gorge 5, or exit the map.

Progress through the stage, past the rabbits and before the pork enemy, there's a mining spot to the left.
Alternatively, you can enter from Radiant River Gorge, Kappa's Mirror, backward into Gorge 5, and keep going left until you reach the mining spot.





Head to the top left path, and continue until you encounter rabbit enemies. Continue going towards the upper left, near a bubble area there will be a mining spot.

Continue along the path of bubbles, in the spot with the two rotating bubbles, there will be a mining spot to the top right of them.

You can exit to the world map, or continue to Cascade 2.

There's a mining spot just before the end of this stage. It's fastest to access by entering from Cascade of Eternal Darkness Depths from the world map, and move backward into stage 2 to quickly access the mining spot.



There's a mining spot to the far right, next to the gathering point.

Besides mining spots, there are a few other ways to obtain ice.

When you unlock trading with the capital, you can trade rice for ice.

You can find ice from the gathering points in Lucid Falls and Hidden Crimson Spring.

When you unlock dogs, you can send people out to Gathering Area: Lake.