Tallnecks are gigantic machines in Horizon Forbidden West that players can use to get a lot of information from. When Aloy climbs to the head and overrides it, a shockwave is sent out, and her map is updated with tons of markers on the map that can direct you to a side objective you want to go to without needing to explore everywhere first. Here are all of the Tallneck locations in Horizon Forbidden West.
Cinnabar Sands
This is likely the first Tallneck you will come across, and it is circling a broken-down satellite. To get to the Tallneck, you need to climb up the satellite, retrieve the power cell there, power up the satellite, and make it spin around, giving you a platform to jump onto the machine.
Landfall
This Tallneck is deactivated after being knocked down by the current and its power cores stripped. You need to climb two nearby areas with bird machine nests to find the cores.
Saltbite
This Tallneck is taken care of by completing Cauldron: IOTA. When you arrive at the cauldron, you go through the process of repairing and activating it.
The Shining Wastes
This Tallneck is overridden as part of the story quest The Wings of the Ten. Just fly your Sunwing towards it and drop onto its head.
The Stand of the Sentinels
This Tallneck is circling an abandoned settlement in trees. On the ground are some Stalkers with Clamberjaws occupying the tree levels. If you have not unlocked Sunwing mounts yet, you will need to glide into the village from the nearby mountain and climb to a point where you can jump onto the head.
The Stillsands
This Tallneck was attacked by some Oseram salvagers using ballistas with anchors on them to weigh it down. When you find this out, you use the ballistas to shoot and slow down the machine so you can climb to the top of it. However, machines are called in and will search for you as you shoot into it.
