As the other two pipe theory's were study's of the pipehistory and nature of pipes, this one primarily focus's on 'Pipe Land' or 'PipeWorld' from SMB3. Before I go into my main study of Pipe Land, I would like to go into small theories besides that. As correctly said before, pipes are indeed organic and grow. But in an area in the Mushroom Kingdom, there is an intriguing and amazing place.
Pipe Land has the strongest concentration of pipes anywherefrom the Mushroom Kingdom. How can this be? The weather or climate effects the growth of pipes indeed or even something artificial. So in the area that is Pipe Land, the climate is very peculiar to have such a strong concentration of Pipes. The citizens of the Mushroom Kingdom have took in fact that Pipe Land is the best place for transportation and has a wide range of areas to go to in the Mushroom Kingdom. Not only is Pipe Land an organic place but since the citizens, being smart as they are, took in fact that it is a very important place and must be used to its fullest. And if Pipe Land would resemble any other climates it would be a jungle since it is very humid there and basically is a pipe jungle, some pipes still as they were since they were born and others artificially upgraded and modified to fit the citizens normal everyday needs.
Aside from being organic, the citizens put in a type of Pipe Plant much like a power plant inside Pipe Land to connect certain Pipes into one and having learned the certain climate in which Pipe Land has grown somuch into, the Pipe Planthas weather capabilities which support the existing climate and take it to more extreme heights greatly increasing the growth of pipes. As for the piranha plants that grow and infest these pipes it has been tried many times to eliminate these piranha plants there so the citizens have grown accustomed to these vicious plants and don't mind them as much.
In conclusion, Pipe Land is a very vital place in the Mushroom Kingdom. It is a key to most of the traveling being done in the Mushroom Kingdom. And since it is the center of transportation in the Mushroom Kingdom and leads to many places it even has the range to go to even the farthest of places of Mushroom Kingdom. Even some pipes from SMW or SMB that do not let any warps take place can still lead all the way over to Pipe Land. Some daring explorers by the names of Mario and Luigi should remove these restrictions from the pipes and find out where they lead to. Bowser's next target might be Pipe Land since it is a vital place in the Mushroom Kingdom.
Pipe Land, a wonderous and nice place in The Mushroom Kingdom.