[Neus]

Read the markers.dm file's comments; it explains how they work pretty well and you can look at the vars of the existing markers and areas; basically, an area with a marker_tag will teleport you to a marker of the same marker_tag when entered. I believe that file (or maybe one of the other ones in there) also explains four-way directional entering for overworld features. If you have any other questions after that, feel free to ask.