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This article is about the Glacial Basin. You may be looking for the Glacial Bay or Glacial Connection.

The Glacial Basin is a large above-ground biome in Subnautica: Below Zero that is accessed from either the Glacial Bay or the Glacial Connection. Players accessing the biome through the Glacial Bay will find themselves near the Phi Robotics Center. Players taking the latter route will find themselves surfacing a lake in the southern portion of the biome. The biome plays a vital role in Samantha Ayou's part of the story.

The biome borders the Glacial Bay and Glacial Connection.


The Glacial Basin is a large, empty basin most likely created thousands of years ago by the movement of a long collapsed glacier. Two notably tall ice mountains–one located near the center of the biome and one located northwest– mark the locations of the caves containing the Phi Robotics Center and the Phi Excavation Site, respectively. The latter also marks the location of Parvan’s Bunker. Multiple Ore Veins and Snowfox fragments can be found throughout the biome. The area also contains the majority of the game’s Spy Pengling sites. The player may trek a full circle around the biome, as it loops.

Towards the south of the biome, a lake harboring a dock contains the entrance to the Glacial Connection, one of the two ways in or out of the Glacial Basin as well as an underwater cave that leads the player back to the frozen river leading to the Phi Robotics Center. The area surrounding the lake harbors the basin’s Pengwings and Penglings.

The Glacial Basin can be devised into seven regions:

The Glacial Basin

The main section of the Glacial Basin is the exterior portion. It is a very rocky biome surrounded by tall, icy cliff sides. The area is dominated by hills, cliffs, and ridges, as well as a few rivers and waterfalls. It also features many blasting vents that can propel the player upwards while riding on the Snowfox. The Basin is the second-largest outdoor section of the map after the Arctic Spires. Numerous Frosted Sinew Trees can be found throughout the area. The north-eastern portion of the basin houses the Phi Robotics Center as well as the river that leads to an underwater cave. The player may ascend a nearby hill to access the southern portion of the biome, which contains the lake leading into the Glacial Connection and the entrances to the previously mentioned underwater cave. The south-western corner of the basin is a series of hills and cliffs, with a small tech site bordering another river where the player can unlock the Snowfox Hop Module. The aforementioned river separates the main basin from the Glacial Forest.


A blue ice cave

These caves are identified by the skeletal remains near their entrances or within the caves themselves, and provide shelter for Snow Stalkers. Fevered Pepper Trees can be found within these caves as well.


A Dark Cave

These caves are distinguished by the Glow Fungi that hang off their ceilings. Two of the caves are nearly pitch black, encouraging the player to use a Flashlight or Headlamp to navigate through, though the only exception is the smallest dark cave containing an abandoned flashlight illuminating the cave as well as triggering biophosphorescence within a few glow fungi. There are three dark caves within the Glacial Basin.


The Glacial Forest

The northwestern portion of the biome possesses a unique region known as the Glacial Forest, an open area populated with Frost Acacias. The entrance to the Phi Excavation Site, indicated by a few crates and light sticks can be found in the northwest corner of the area.


The Ice Fissure

This unique region is characterized by the unique ice wall formations, as well as the ice composed floor. This fissure hosts one flora species, Frost Vase Plants. Ore Veins can be found within the fissure. If the player is not cautious, they may fall into the area from above. The player can enter the fissure safely by climbing down a set of ladders positioned near the edge of the area, or through a hole within the side of a cliff. It is located northwest from the Phi Robotics Center.


Overview of a temperate cave

These caves are characterized by their Ice Stalagmite growths and exclusive Marbled Anemone. The largest of the temperate caves contains an underground waterfall leading into a small river. The temperate cave serving as one of the two Glacial Bay entrances to the Glacial Basin contains a Pathfinder Tool fragment. Fevered Pepper Trees can be found within these caves. There are three temperate caves within the Glacial Basin.


An underwater cave

Two underwater caves are located within the Glacial Basin. The underwater caves have rocky, sandy floors, and house several stalactites covered with green, self-illuminating spots. Whether these are organisms or part of the stalactite itself is unknown. Both caves host a handful of Arctic Peepers and Bladderfish. Small, harvestable flora can be found around the Hydrothermal Vents within these caves. Seagrass from the Arctic Kelp Forest dots the cave floors. Sealed Ice Bubbles and Ore Veins can also be found within both caves. The southern underwater cave takes the player to and from the Glacial Connection lake and the frozen river that leads to the Phi Robotics Center. The northern underwater cave takes the player to and from a temperate cave and a path back to the Phi Robotics Center; it is also accessible from a hole above the cave.



  • Early in development, the Glacial Basin originally had the goto ID hoverarea.
    • This makes the Glacial Basin one of the three original "Hover" biomes, the other two being the Arctic Spires (hoverzone2) and the cut Hoverzone 3.