On a world with no map, knowing where you are is knowledge — and it lives in players’ heads and in screenshots pasted into Discord. Cairn moves it into the world, where it can be built, found, lit, and lost.
It adds no pieces, no assets, and nothing to your screen.
Building A Cairn
Stack four stones. Placeable_Stone is a vanilla Hoe piece costing one stone each, so a cairn is four stone and a minute’s work. Keep each stone within about 2.5 metres of its neighbour — the links chain, so a curved pile still counts as one cluster — and keep the whole pile under four metres across; spread past that and it reads as a building rather than a waymark, because a cairn is narrow and a building is wide, and that is how the mod tells them apart.
It lights itself. Within about ten seconds a fire appears on the crown, and it can be seen from hundreds of metres away.
Name it, if you want. Put a sign within six metres and write on it, and the place has a name. A cairn with no sign is still a lit waymark — plenty of them should be.
Every one looks different because you built it, and uninstalling the mod leaves exactly what it appears to be: a pile of rocks with a sign on it.
The Light
It holds its size at distance rather than shrinking away — a fire on a far headland reads as a point of light the way a real one does, not as something that gets small until it is gone. Seen down a chain of fifteen cairns spanning 420m.
And it is hidden by terrain. A ridge between you and a cairn puts it out, so you have to move to see it. That is the difference between navigating and being told, and it is the reason this is a beacon and not a marker.
Colour is yours: BeaconColour takes hex — 4A9EFF for cold blue, 7CFF7C for something stranger. The default is firelight.
The Raven
Stand at a named cairn and Hugin may land and say its name.
He is fussy, and deliberately so — vanilla will not land the bird below 30 metres of altitude, with anything hostile within ten metres, or during a world event. So he is silent exactly when you would most want him, which is why nothing in the mod depends on him. He is a grace note, not a compass. cairn raven will tell you why he has not come.
What It Does Not Do
No map. No compass. No waypoints, markers, pins, arrows, HUD, or readout of any kind. If you learn where you are, you learn it by looking at the world.
It adds no prefabs — a cairn is recognised, never provided — ships no assets, and leaves vanilla recipes alone by default: StonePileStoneCost is the one setting that touches one, and it does nothing at its default of 0.
Technical Specifications
| Parameter | Detail |
|---|---|
| Runs On | Client & Server — one DLL, all three roles |
| Target Runtime | BepInEx 5.4.2333+ |
| Engine Target | Valheim (Unity Engine) |
| Requires | Valheim 1.0.7 or newer |
| Current Version | 0.8.0 |
| Prefabs Added | None. A cairn is detected, not provided |
| Persistence | Landmarks stored per world, beside the save, in plain text you can read |
Configuration
Everything is in BepInEx/config/com.raveniron.cairn.cfg, and every value carries a note explaining what it costs. The ones most worth knowing:
| Setting | What it controls |
|---|---|
PileMinPieces |
How many stones make a cairn (4) — raise it if decorative stones start lighting up |
PileMaxExtentMeters |
The footprint that separates a waymark from a building (4m) |
LandmarkPairMeters |
How far a sign may stand from the cairn it names (6m) |
StonePileStoneCost |
Stone cost of vanilla stone_pile — 0 (default) leaves it alone, anything else rewrites the recipe |
BeaconColour |
Hex, RRGGBB |
BeaconMaxDistanceMeters |
How far a light carries (800m) |
BeaconOcclusion |
Terrain hides beacons. Leave this on |
LandmarkRotationSeconds |
How quickly a new cairn is noticed (20s) |
EnableRavenVoice |
The bird |
Console
cairn status · landmarks · beacons · raven · prefabs <text> · pieces <text> · save
Each reports state rather than verdicts — beacons says whether a light is out of range or hidden behind a hill, raven says which of four reasons the bird is quiet for. They exist because guessing at each of those cost an afternoon.
Installation
Install on the server and the clients. One DLL does all three roles: a dedicated server sweeps the world and owns the ledger, a client draws the lights and carries the raven’s line, a listen host does both.
Compatibility
Nothing is patched that another mod is likely to want. Environment and weather are read-only, so the season mods are untouched; no prefab is added, so no save is at risk; and nothing is written to Minimap, so a map mod and this one simply ignore each other — though running both does rather blunt the point.
Part of the RavenIron Suite
Every RavenIron project is engineered server-authoritative in C# and .NET, and shares the same forge.