The Plane of Ice is a special level in SpliceHack. It is part of the Elemental Planes, appearing between the Plane of Air and the Plane of Fire.
The level is largely composed of water. Regions of ice move, disappear and reappear: these represent icebergs. The portal to the Plane of Fire also moves.
There are eleven ice elementals, three plasma elementals, one air elemental, one water elemental, two red dragons, one silver dragon, one white dragon, two energy vortices, and two ice vortices: all of them are guaranteed to be hostile. Additionally there are two krakens, four random ;, and twenty other random monsters.
The entire plane is lit. 
Levitation or flying is best for crossing the water. It is also possible to jump, which can sometimes be useful for escaping nearby monsters.
Throne Archons and liches can be generated on this Plane, see you from far away, and start summoning nasties around you.