Caves

## How to access caves and mines

There are various caves on the map, most of which are tunnels. At the beginning many are blocked by ice, which melts away in stages as you progress the terraforming process.

* Stage 1 melts at 175 kTi.
* Stage 2 melts at 5 µK Heat.
* Stage 3 melts at 45 µK Heat.
* Stage 4 melts at 32 GTi.

Caves have their own lighting, but a flashlight is still useful. All caves can be walked through without building structures or using a Jetpack, but these are still useful in some of them.

## Small caves

### Osmium Cave

There are at least five locations that have been found. All of them are initially blocked by ice. One of them will be underwater after the Lakes milestone. Most Osmium caves are all rock and will not support Extractors.

* Tunnel connecting Steep Hill to Sulfur Fields (has soil)
* Under the falling sand in Sand Falls (no soil)
* Tunnel connecting the Cracked Spires and the Wasteland. It contains iridium ores on the Cracked Spires side entrance. See below. (has soil)
* Tunnel connecting the Arches to the Pulsar Quartz cave, and through there the Meteor Crater. (no soil)
* Tunnel connecting the Grand Rift and the Dune Desert (no soil, submerged)
* (Not anymore) Under a sinkhole in Gate Desert, but after 0.4.14, this Osmium Cave became a Pulsar Quartz Cave, and in saves created prior to this, the cave will still have Osmium and Sulfur there.

All of these caves have both Osmium and Sulfur lying around. An Ore Extractor T2 placed in any of these caves (except the flooded ones) will collect Osmium, **but Ore Extractor T1 will collect Iron, not Sulfur.**

### Osmium-Iridium Cave

The Osmium-Iridium cave is located in the south of the map (coordinates 361:10:-181) in the Cracked Spires (it is connected to the Wasteland). An entrance can also be found in the Barren area, coordinates 89:31:-303. There is a layer of ice that has to melt in order to access a half of the cave. The entrance to it is really narrow. It contains a bunch of Iridium and Osmium. The ground is purple, and there are multiple platforms to jump on, some of which will lead you to a crate if you parkour enough. The fog is blue and there are Osmium crystals on the ceiling. It also contains some Sulfur.

### Iridium Cave

The Iridium Mine can be found northeast of the Starting Valley. It connects to the Sulfur Fields.

The second Iridium cave is on the east wall of The Grand Rift. It is located southeast of the landing pod if you chose The Grand Rift as starting site. Coordinates: 2027:3:-45

The third Iridium cave connects the Cracked Spires to the Wasteland. It also has Osmium in it (see below: Osmium-Iridium Cave). Iridium cannot be extracted here.

### Uranium Cave

The Uranium cave is located in the Gate Desert, entrance coordinates 585:38:-664. A narrow, zigzag slot canyon offers a shortcut to the Cracked Spires and Aluminium Hills.

A second Uranium Cave is in the northeast portion of The Highlands. Its entrance is pretty tight and is easily missed. The Coordinates are approx. 1779: XX: 1984. An Ore Extractor T2 can be placed in the far corner.

### Pulsar Quartz Cave

This cave emerges in the Meteor Crater, and backs onto an Osmium Cave that comes out in the Arches. It is long, narrow and tortuous, and filled with thick maroon fog. It contains a couple crates and several nuggets of Pulsar Quartz, but does not have any mineable terrain at all.

A second Pulsar Quartz cave can be found under a sinkhole in Gate Desert with the entrance at 971:41:-981. During the Lakes stage, the sinkhole will fill with water, submerging the cave. Prior to version 0.4.14, this was an Osmium cave, and in saves created prior to this, the cave will still have Osmium and Sulfur there. An Ore Extractor T1 placed on the soil above this cave will collect Sulfur.

### Super Alloy Cave

The Super Alloy cave is located in the south-west region of the Dune Desert. Its entrance features a conspicuous overhead shelf and several massive rock columns, looking almost deliberate. The coordinates to the entrance of the cave are 1075:65:1702.

In the north wall of the Super Alloy Cave is an immense pair of stone doors, shut tight. The lore update added (spoilers...):

  the ability to open the stone doors, an alter sits before the door and requires a warden's key to open.
## Cave biomes

### Iridium Mine

The Iridium Mine can be found northeast of the Starting Valley. It connects to the Sulfur Fields. During the Flora stage, a large climbing vine grows that grants access to the Balcony. Either tier of Ore Extractor will collect Iridium, and Iridium can also be found loose.

### Mushroom River

The Mushroom River can be reached through cave entrances in Meteor Field and Waterfall. No extractable minerals can be found here, but there is plentiful water and interesting scenery, and the best Butterfly Larvae can be found here.

### Zeolite Cave

The Zeolite cave is located above the Meteor Crater with entrances via an Osmium Cave located in the east, in the west through the Arches and in the south via the Meteor Crater. An Ore Extractor T2 will collect Zeolite.