In the land of the vast green fields... Rows of guiding graves...

A green land surrounded by cliffs. The arena has four hill-like graves, with stairs that lead to the basement. The basement is connected by a narrow passageway, and you can move to any of the stairs. At the back of the arena there is a platform in which the colossus sits on when first finding it.

The arena is located at the center of the Forbidden Lands, southeast of the Shrine of Worship, at quadrant G5.

It was discovered by Nomad Colossus that Agro once had an AI path on the pit by the entrance of its arena, being able to go up and down its ramps. It's unknown if that area ever led anywhere.

An early version of the arena appears in the NICO Trailer. The evidence for this was found by a fan named Aith, as he was playing around with the arena's 3D model he noted "On each corner of Phaedra's platform the verticals are arranged in a distinct circular pattern that appears to have been hastily patched." Suggesting that the four pillars seen in the footage were actually for the colossus' starting platform.

A glimpse at a more recent early version of the arena (seen in the gallery below) can be noticed in the September 2004 Production Presentation trailer.

A low quality recording from a trailer posted by IGN features the same glimpse but without the flashes at the end.

Near the end of development, the entire arena was mirrored horizontally and moved to the northeastern side of the quadrant as opposed to being in the southwest, as proven by the early pause menu map, ambient texture and super low resolution texture of G5. The model in the E3 Demo version still has the old sunlight baking.

A piece of this non-mirrored version is also seen in the ending model from the E3 Demo.

In the E3 Demo, the theme Sign of the Colossus plays when first entering this arena. The cutscene's camera goes through the walls of the stage since it was mirrored recently. Reversing the mirroring and placing Kirin's Hill in its original location makes the cutscene play out nicely.

A stage segment in the PS3 data sheets was found to contain information for seamless models which start with "g4_kirins_hill_...", and their texture segment is set for "texseg_g4". The seamless models are set at layer 3, a layer that doesn't exist anymore (only layer 0 and 1 models exist in the final game), and its chips suggest that it was only for the entrance to Kirin's Hill; that being the outside area before going inside the ravine leading to G5.

Several texture segments for separate objects named "kirin_A_stone" exist in the PS3 data sheets. Those include a "core" and 11 parts for when it "breaks". Those are named similar to the structures that fall on top of the 14th colossus' head in Ruins and the rocks in Stonehenge.

The early specification of the arena has the boss spawn on top of a large hill, which is likely the "Kirin's Hill" the arena is named after. This means the namesake of the arena was actually removed fairly early on