There are three main ingredients that overlap with all gear-related trade skills in New World and iron is one of those precious things to have. Here are a few great spots to farm the ore and a few tips on maximising the yield.
Mining iron ore in New World is fairly straightforward since there are numerous nodes all over the place but the immense demand often makes players go hungry for more in order to progress their trade skills. Therefore, using their time to the maximum is a priority, meaning you will want to get as much iron in as little time as possible. Here are a few locations to keep in mind, whenever you run low on the material.
This is easily the best but also the most popular place to farm iron. Not far from the town, you will find Stonereach Pass which has an extremely high concentration of iron veins. The location is slightly to the west of Everfall and is the place of PvP quests so you will want to turn your PvP off in order to avoid getting ganked while mining.
You can see the exact location on the map below, as well as a zoomed-in version of the pass itself, with a marked path you will need to circle, in order to find all the nodes.
As I noted previously, this is the single best zone to farm iron but many players are aware of this so you will have to compete with them, effectively reducing the zone's allure. Try farming here when it's the dead time of the server, to minimise the chances of other players mining the place.
My favourite place to head to in case I discover others are farming Stonereach Pass. Just keep going south from Stonereach, along the mountains and you will find several iron nodes along the way but the exact place where you have a great concentration of veins is along a ridge south of Monarch's Bluffs settlement.
The ridge, shown with a solid red line on the image below, is the main route for farming but it does have fewer veins than Stonereach, meaning you will likely drain them all before the first one respawns. If that happens to be the case, visit the additional two red spots I marked as they also have iron.
This one is not worth farming on its own if you're looking solely for iron but if you're farming it alongside starmetal, this is an excellent spot as you can farm both in the same run. The nodes should start respawning before you are through with the entire circle, meaning you won't be wasting any time between the ore veins.
Weaver's Fen is not as filled with players as the other two areas, giving you a better chance to mine in peace. There are a ton of skeletons in your way along the road that leads to iron though. Good luck.