Hollow Earth

The term **Hollow Earth** refers to a series of "pockets" in the Earth's crust which sustain macrobiotic life. These pockets are lit by massive luminescent crystals, which allow for plant life to maintain a breathable atmosphere. Seismographic equipment fails to note their presence due to numerous factors.

The term itself is a misnomer - unlike the thoughts of some scientists and numerous pieces of fiction in the 16th through 19th centuries speculated, the Earth is not in any way consisted of layers alternating between atmosphere and geologic masses, as Edmond Halley theorized. Rather, the life-sustaining pockets are relatively small, the largest only reaching the size of the Hawaiian archipelago. However, geologic events can cause passageways to form, which can be filled with either water or atmosphere. The most extreme example of this is a former connection between the Savage Land and the pocket beneath Skull Island, which are separated by over 8,000 kilometers.

Perhaps the most notable element of the Hollow Earth network is in the furthest regions - in some places, unexplained spatiotemporal anomalies lead to the deepest "layer", a pocket dimension believed to be the original home of the Kaiju.

## Description

The segments of the Hollow Earth

The crystals that

In many cases, the wildlife in Hollow Earth pockets are descended from populations that are otherwise extinct on the surface, including such groups as dinosaurs, pterosaurs, non-mammalian synapsids, and other prehistoric fauna.

### "Hollow Earth Energy"

One of the most notable aspects of the pocket dimension is the exotic energy source found throughout it, simply referred to as "Hollow Earth Energy", abbreviated as HEE. HEE is of unknown origin, but likely related to the structure of the pocket dimension itself, and is radiated throughout it. HEE is usually a glowing blue substance in its natural state, which has led to speculation on that being the source of the Gojiras' "atomic breath".

## History

### Creation

The creation of the Hollow Earth remains a mystery. The network is almost certainly an artificial creation by an ancient alien civilization, the most common contenders being the Precursors or Mala'kak.

### Kaiju

The Hollow Earth's connections to the surface began at minimum 360 million years ago, at the beginning of the Carboniferous period. It was around that time that the first lifeforms to expand downward, and those that reached the furthest most pocket began to be exposed to the exotic radiation generated in the pocket dimension, resulting in the creation of Earth's Kaiju. While most remained in the Hollow Earth, some species reached the surface world, most notably Gojiras, MUTOs, Mothras, and Rodans.

### Atlanteans

The Hollow Earth appears to have been known to several ancient human cultures, perhaps most notably the Atlanteans. To this day, many societies retain folklore of their ancestors coming from caves beneath the earth, including numerous Native American peoples, and many other cultures note strange creatures or otherworldly beings emerging from underground, noted by the ancient Greeks, Celts, and Indians.

### Modern discovery

The Kaiju-researching organization Monarch

The alpha titan Ghidorah was found

## Known Pockets

### Savage Land

The

there are traces of alien interference in the creation of this particular pocket, with likely contenders including the Forerunners, Nuwali, and even the Celestials.

#### Hidden Sea

The Hidden Sea is an extension of Skartaris,

## Known Entrances

### Antarctica

Antarctica is notable for having two Hollow Earth entrances - The "Vile Vortex"

### Arctic Circle

The North Pole contains several passages to Skartaris.