As our artifact was from the Tibetan area, we decided that this would be a good place to base our environment from. Tibet has a wide range of different places, mountainous and plains, jungles and forests. This allowed us for a very interesting range of places for the player to visit.
I first looked into how the Empire would look. For this, I looked into high density areas such as Delhi in India as it's densely populated. Of course, I also looked into Tibetan architecture and incorporated common themes into the designs as well. For each area I designed, I looked into real places that I drew inspiration from, such as Ta Prohm, an ancient overgrown temple. I varied as much as I can between the different places the player could visit, from the Empire to ancient ruins etc.
Inspiration and resource images:
From the above images, I gathered common themes from each of them, through architecture and how the environment overruns the ruins etc. and tried to incorporate them as best I could in the images below.