Especially in BYOND, teleporters are among the most popular turfs in the game - whether you make the edge of one map take you seamlessly to the edge of another, or if you actually have teleporters and portals, they're pretty useful.
It's not readily apparent how to use teleporters with the library though. Try this!
turf
teleporter
icon_state = "blue spin"
var
destx
desty
destz
Entered(mob/M)
if(istype(M))
if(!M.key)
return
spawn(0)
if(destx && desty && destz)
var/turf/T = locate(destx,desty,destz)
set_pos(T.px, T.py, 0, T.z)
else
M << "Teleporter failed, destination not set!"
Now all you need to do is place a teleporter turf on the map, then right-click and Edit it. Set the destx, desty, destz properties to the location you would like it to teleport you to.