Monolith

Monolith (モノリス Monorisu) is a barrier infused with Varanium.

Description
Monoliths, dark-colored barriers, 1.618 kilometers in height, and 1 kilometer in width, were created from Varanium after mankind lost the war against Gastrea, in the year 2021. The magnetic field emitted from Varanium prevents Gastrea from approaching the Monoliths, let alone enter the protected areas. However, in spite of the strong magnetic field they emit, Gastrea, in very rare occasions, are able to invade the areas surrounded by the barriers. Seitenshi, protector of the Tokyo Area, once stated that the Monoliths stand no chance against the power of a Stage V Gastrea, also known as the Zodiac Gastrea, and that if one is released, it would mean the destruction of the world. It is, broadly speaking, believed that the entire world relies on these barriers for survival and protection.