In my extensive article on Hyrulian geography (A Good Look at Hyrule's Geography) I was able to harmonize, for the most part, the maps of Hyrule given in LoZ, ALttP, and OoT. However, I left an important issue unresolved: the identity of the Death Mountain area.
The Death Mountain area (or DMA for short), for those unfamiliar with Hyrulian geography, is the name given in the AoL manual for the area south of Death Mountain. Here's a picture:
As usual, let's call the area north of Death Mountain in AoL northern Hyrule, and the area south of Death Mountain (featured in LoZ, ALttP, and OoT) southern Hyrule. The problem with the DMA is that it can be either of two things: (1) southern Hyrule itself, or (2) a small area of land between the larger northern and southern Hyrule. For further reference, see my previous article on Hyrule's geography, under "The AoL Map."
The Key to the Whole Mystery
There was one Hyrulian landmark that, through ignorance and indifference, I overlooked in my previous article: Spectacle Rock. Amazingly, Spectacle Rock is the only landmark that is explicitly named in LoZ, AoL, and ALttP, and I completely overlooked it. Spectacle Rock is located on Death Mountain, and is so named because its two jutting stones look like spectacles (glasses). Let's examine Spectacle Rock's location in the three games.
LoZ - In LoZ, Spectacle Rock is the entrance to Ganon's lair. Quote: "SPECTACLE ROCK IS AN ENTRANCE TO DEATH". You can expose the entrance to Ganon's stronghold by bombing the left rock of Spectacle Rock. Spectacle Rock is circled in black on this map:
Here's a screenshot of Spectacle Rock:
AoL - In AoL, Spectacle Rock is located in the infamous Death Mountain Area. In the picture of the DMA given at the beginning of this article, Spectacle Rock is the two rocks in the upper left. Quote: "HAMMER... SPECTACLE ROCK... DEATH MTN." If you use the hammer on the right-hand rock of Spectacle Rock, you will destroy the rock. This opens up a hole leading to a network of underground caves (Ganon's old lair in LoZ, perhaps, or maybe a different part of the Underworld). A magic container is hidden here.
ALttP - In ALttP, Spectacle Rock is on Death Mountain, west of the Tower of Hera. Quote: "Link, it is I, Sahasrahla. You must somehow make your way to the top of Spectacle Rock. From there you can reach the Tower of Hera on top of Death Mountain." Link reaches the Tower of Hera by warping to the Dark World (where Ganon's version of Spectacle Rock doesn't stick out of the ground), getting atop of Spectacle Rock's double, and warping back to the Light World. Now on top of Spectacle Rock, he can jump off the north side and walk to the Tower of Hera. Here is a screenshot of Spectacle Rock:
The entrance on the south side of Spectacle Rock leads to a series of caves in Death Mountain. Here one can read Sahasrahla's tile message to Link telling him to get on top of Spectacle Rock.
OoT (?) - This is a long shot, but Spectacle Rock might be in OoT. It is nowhere specifically named, however, so this isn't certain. If you go inside Death Mountain Crater and look at the middle, you will see two large jutting rocks, with the warp platform in the middle of them. It is possible that this is Spectacle Rock. Presumably, after OoT, Death Mountain Crater filled with lava, leaving Spectacle Rock jutting out of the ground. The location of Spectacle Rock seems to be consistent with the location of Death Mountain Crater. (To see that this is true, look at the Complete Hand-Drawn Maps in my previous geography article. On each map, move down Death Mountain Crater so it is in a direct line west of Zora's Fountain. On the ALttP and LoZ maps, replace Death Mountain Crater with Spectacle Rock. You should see how Spectacle Rock appears to fit in perfectly in Death Mountain Crater's place.)
Spectacle Rock and the DMA
Now, having straightened out the facts about Spectacle Rock, several things immediately become apparent. The Death Mountain area must either be: (1) southern Hyrule itself, or (2) a small area within southern Hyrule. This arises logically from Spectacle Rock's location in LoZ, AoL, and ALttP. The extent of Death Mountain shown in these three games is all of Death Mountain there is, and Spectacle Rock is in the southern part of it. The DMA must therefore be south of Spectacle Rock.
It is tempting to simply conclude that the Death Mountain area is southern Hyrule. The evidence for this possibility is strong. As mentioned in my previous geography article, the DMA looks a lot like southern Hyrule. It has the central lake, the forest and graveyard to the west, the smaller lake to the east, Spectacle Rock in Death Mountain. The DMA is surrounded by water on the south, east, and northeast. This corresponds perfectly to the map of Hyrule given in LoZ. One might object to this possibility because southern Hyrule seems too small in comparison with northern Hyrule. But, as mentioned previously, the AoL map is zoomed out with respect to all the other maps of Hyrule, so it shouldn't be surprising that southern Hyrule should appear a lot smaller than it does in other games. And, when you think about it, southern Hyrule isn't that large an area.
Despite the strong evidence in favor of the above possibility, the other possibility is still viable. Consider the map below. It is taken from the 80s comics. I show it not because I want to accept it as canon, but only because it illustrates perfectly the other possibility I am speaking of.
Notice how this map splits Death Mountain by a river flowing from the northern ocean (as in ALttP). The map puts the DMA (1) south of Death Mountain, and (2) north of the large lake in the middle of Hyrule Field.
I think that this placement is a potent possibility. It is true that on the LoZ map, neither the DMA nor the river from the north appear. But both landmarks could have formed in the years between LoZ and AoL. It can't take that long to form a few small lakes and grow a few small trees. The lake flowing from northern Hyrule through the center of Death Mountain existed in ALttP, and could have been blocked up afterwards. It could then have been let loose again after LoZ. Another point in favor of this possibility is that it puts Spectacle Rock in the right scale. If the DMA is southern Hyrule, Spectacle Rock seems much too large. If the DMA is only a small part of southern Hyrule, Spectacle Rock is just the right size. (Of course, everything on AoL's overworld map is exaggerated out of scale anyway, just to emphasize certain landmarks.)
I would have loved to close this issue once and for all, but, in fact, all I have done is narrow down the possibilities. The DMA either is southern Hyrule, or it is a small part of southern Hyrule. To me, both possibilities seem equally viable. Perhaps the first possibility relies less on speculation. But until I come up with more evidence, all I can say is, believe what you want to believe. If you want a complete, unified map of Hyrule, believe that the DMA is southern Hyrule. If you don't like the idea of southern Hyrule being so small in comparison to northern Hyrule, believe that the DMA is just a small part of southern Hyrule.