Site Pylons are a railway item in Astroneer. They allow for the creation of rail lines, and can be used to recall Rail Engines to the Site Pylon. They spawn on Glacio and Calidor near mission items.
Site Pylons will connect rail lines to any other pylon, Rail Post, Tall Rail Post, or Rail Junction. They are best used with Junctions, as the Site Pylons are a dead-end.
Site Pylons may be picked up and moved for better placement of rails. The Packager can be used on it for better transportation.