Today, on a lark, I peek at a glowing light under the ocean. My curiosity getting the better of me, I have a good look only to find a semi dilapidated and slightly looted string of track extending into a well lit and narrow passage.I find some nearby metal and proceed to find where the tracks go. Previously, my frontier excursions have yielded some fascinating architecture for observation. I decide to see where the tracks take me.Repairing the tracks and stopping lava flows, I find the tunnel continues eastward but lacks additional track. My freshly constructed mine-cart doubles back and I collect my own stash of wood and iron bars. To the project I add roughly 3 full stacks of iron rail with electrified pushers.Shortly thereafter I find the tunnel has stopped, a lava pool of significant volume has halted construction. I divert the lava and tunnel through while replacing liquid stone with solid. This takes some time. Breaking through into another tunnel's end, I then find that the tunnels original builder had given up on one end and started to tunnel from the intended terminus and so the two tunnels find a connection.Running and consuming a good sum of food in the process, I finally find the tunnels ultimate purpose. The massive project results in a semi convenient path to a very simple box home with wide windows. Perhaps the purpose of the tunnel was merely to dig.Having spent several hours repairing this elongated spider haunt, I realize that such large over-land lengths of steel are excellent for transporting one's self through a large mine complex but are impractical as a mode of long distance travel over the Frontier's surface or beneath it's rocky strata. A dual-portal bearing track-way through the Nether via a fortified tunnel or along the fiery domain's entombed heights will yield eight times as much distance traveled for the same length of track.As tempted as I was to rip up all the track, I may simply reclaim what I laid for a more suitably planned project. If this person ever decides to finish their tunnel, may I suggest the tracks be moved to the Nether.