It's also known by its scientific name, the Fourth Dimensional Core Square Ring (四次正角性中核環, shiji seikakusei chuukakukan?, lit. "Autostabilizing Nuclear Tesseractal Loop"), and it could be said that it's the next level after the Triangular Nuclear Loops, which serve as the Hearts of the Reyvateils.
The Hearts of the Land have generally the same shape, but their size is highly variable: hypothetically, at their max size, they could create a continent several thousand Stons in size.
Its FFT Spectrum Oscillation Limit is of 1 x 10^20 Hz.
A Heart of the Land is fundamentally made from three parts:
This is the Heart of the Land itself. It's usually located at the very center of the continent, and it's a plasmatic existence, given it doesn't have an actual form.
It's a crystal whose function is to protect the Core. Given that the Core doesn't have a physical form, and thus, wouldn't be able to exist in the world, it also has the function of storing the Core to allow its existence. When talking about a Heart of the Land, the Core and the Core Glass are referred to as if they were a single entity.
This is a part that resembles multiple shells rotating upon each other, all having the core as their central pivot. Each one of these shells rotate independently from the others, covering any gaps and crevices that might exist within them, and are structured in a way that makes impossible to take out the Core from within them.
Its main role is protecting the Core from the outside world, both from the physical impacts (D-Waves) and from the mental interferences (H-Waves), and also, prevent any damage from being done to the Core from the negative feelings that exist in the world. If the Core was removed from the Shell, it would be eroded by the influence of the negative feelings that fill the world, and before a long time, it would vanish completely. That is the main reason for the existence of the Shell, though also, because nothing can penetrate these multiple layers of rotating shells, nothing is able to extract the Core from within.
However, by conversing with the Heart through a Song, and demonstrating that you don't hold any hostile intentions towards it, you could be able to extract the Core from the Shell.
So far, the only method known for creating a Heart of the Land is using the song of creation, Metafalica (song), but given that this method also extracts the Triangular Nuclear Loop or LEM of the singer, or any Reyvateil near her, and ends killing them, it has never been put into use.
It's also possible to extract a piece of the Core using a song, which will in turn create a new and independent Heart of the Land. However, the new Heart will be empty and unusable, and will have to be filled with feelings from a great number of people before it can accomplish its functions.
- Apparently, there isn't an official consensus in the English localization for how the scientific name should be translated, since it appears at times as 4D Conformal Nucleus Loop and Fourth Dimensional Core Square Ring.