Not much is known about the world in which The Last Guardian is set.
A place shrouded in mystery, and for good reason. The Nest is comprised of a massive, crater-like valley surrounded by sheer, impassable mountain walls that can only be bypassed by air. Most of the Nest's interior is filled with crumbling castle ruins with towers, courtyards, bridges, passageways and temples. Underneath the surface are endless tunnels, some of them flooded, others barred by huge rusting gates of iron. Overall, the buildings and stonework are heavily overgrown with lush, green ivy, as well as trees and other plant life. No one knows who built all the castles, who may have lived here before, or what happened to these masters of architecture.
The ruler of this picturesque, crumbling landscape is an evil being known only as the Master of the Valley. It controls all the inhabitants. Amongst its servants are the Tricos, huge, winged griffin-like beasts and an army of possessed, living suits of armor called the Armored Knights. Only the Tricos can leave the Nest to do the Master's bidding, as they possess the ability to fly. Other inhabitants include unknown species of birds, salamanders and butterflies.
The Outside World
Little is seen of the world outside the Nest. It seems to be heavily wooded, as far as the eye can see, with a temperate climate. Rain and lightning storms seem as common as they are in the real world.
Dotting the thick trees are man-made clearings with villages. The village designs seem to mainly consist of a wide open clearing, with the houses hugging the treeline. These villages are inhabited by clans of humans. The humans seem to be at a simple technology level, as the villages are lit with torches, and weapons consist of throwing spears, bows and swords with no armor. Little is seen of the wildlife, but given the vibrantly green environment it may be fairly diverse.