The towering gates of Konohagkure no sato can be seen quite clearly from the opening forest path towards the large, grand, wooden gates that presented themselves towards any who took the traditional pathway towards Konoha. Far higher than any building in the village, from the ground, it would be nigh impossible to see the village without the gates being open. Incredibly thick and exceptionally strong, possibly created by the powerful Wood Release that seemed to have been used to construct most of the entire village, this wall serves as a perfect defense against most elemental natures.
However, because it is wooden, it is beleived that a powerful enough fire technique could set it afire, although most fire techniques tend not to be able to do so, potentially becuase of the very nature in which they were created, with the fusion of earth and water chakra that formed Mokuton toger being rather resistent to fire in general seperately, both combined enhance such protection. There are probably other added factors that have made the walls resistant to heat damage.
One final, very major thing to note is that the wooden walls are not only tall, but are rather thick, making it rather difficult to go through with even A ranked jutsu specalized in wall tunneling. Termites and the like seem to not have their way with the wall, but maintanence and the avid amount of Mokuton users in the village, particularly the current Hokage Tommi Uematsu or just "Tomi" for short suggest that any pest problems are very quickly taken care of.
There is one main gate at the southern wall, and althought he gates themselves are both thick and tall, compared to the wall itself they present a potential weak point, but it is not one easy exploited as the gatekeeper's post, which is carefully situated near the gates, yet a large portion of it hidden from view, provides gatekeeper's with a clear view of oncoming attackers without themselves being exposed.
An unseen mechanism controls the opening and closing of the gates, and once closed, the gates become just as resiliant as the walls that they are made into. A full 200 degrees around the village the wall goes, stopping only due to the Mountain that Konohagakure resides beside, the mountain itself to be described in another post. Eastern and Western gates, both hidden from the general populace and well concealed from intruders, offer another route for Leaf shinobi to enter the village, although they are far smaller in comparison to the Main Gate. To open these gates require special permissions and possibly even fuinjutsu that are known only to those with the proper authorization to use them.
Specific Defenses:
Konohagakure employs various amounts of defenses for the village itself, particularly barriers that extend even beyond the physical presence of the village itself. The barrier is technically a double barrier, invisible to both the naked eye and some doujutsu, both "layers" sustained by an obelisk hidden within Konohgakure itself, though considering the structure of the village probably near its very heart, guarded by the Hokage's Mansion. The exact location is hidden for even the ANBU Captain of the village, the location defended by powerful seals that prevent peering doujutsu or even the most power sensors of chakra from locating.
Those few whom are allowed access to the obelisk, as it does need to be fed chakra every now and again, are constantly under watch by ROOT ANBU and supposedly the leader of the ROOT as well. In fact, there are rumors that the only ones who are not under scrunity when delivering chakra are the Hokage and the obelisk's guardian.
Inner: The inner barrier was created through the efforts of fuinjutsu experts within the village, as this barrier is practically an alarm system, allowing the Hokage and assorted defenders to instantly be aware of someone enteirng through this barrier, regardless of whether they are friend or foe. Their chakra signature is also recorded, allowing for hunter nin to trace the signature with signatures of known enemies, particularly rogues or missing ninja from the village.
Outer: The large scale outer barrier is also in the form of a sphere, including a portion underground. However, this barrier has been dubbed: Fūjutsu Kyūin, or the "Blocking Technique Absorption Seal" due to the fact that it can completely reverse chakra based attacks, particularly ninjutsu and potentially even genjutsu. Highly advanced, the chakra taken can also be used to fuel the obelisk, making a mass scale ninjutsu attack the perfect power source, as although the obelisk does not possess limitless chakra, it has a very high storage amount. It is rumored that even senjutsu could potentially be stopped, as the normally undesirable effects of absorbing senjutsu chakra is not as dangerous, particularly if a sage is monitoring this technique.
Both of these barriers are spherical in nature and extend about 20 meters out from Konohagakure (note that this is actually somewhat inside the defending forest and mountain range) and possess a height (and depth) of 400 meters, making it maintain an appearance far more like a large, 3-D oval rather than a sphere.The Great Senju Wall
The original wall structure of the village was re-constructed with the re-initiation of Tomi "Uematsu" Senju as the acting Hokage. The original wall has been completely reinforced, with only one true entrance into the village, the other "entrances" now created as a method for trapping unsuspecting infiltrators into the village. It is noteable that there are now even more lookout towers than before, each equally distributed along the wall and having a minimum of two people manning these towers. All of this, the wall itself, was reconstructed using the most recent Mokuton of Tomi's Sennin Moddo (Wood Style while in Sage Mode basically) creating a wood that is far more durable than metal, without the deadly rust effects of metal itself. Due to the creation method, the walls require less physical maintanence, but do every now and again require "trimming" as sometimes branches grow out from these walls, at one point literally encloaking the walls and the entire outer perimeter of the village in leafy branches...
