Warichaa

Warchiaa was the largest concentration of on Advan. It was an underwater city, with a small portion above known as the Oyster on the Water. It was made up of underwater caves converted to dry, liveable caves, glass domes, and pre-made buildings. It earned the nicknames "Oyster on the Water" and "Shell City" from the octagonal pre-made buildings on the surface that are arranged in a hexagon. Thus it looks like an oyster shell floating on water.

Surface Facility
The surface structure was used to first drain the area where the city would be built, lower in materials, and later filter the salt water for both the city and nearby Zenith. A cement wall was built in a 2 kn octagon to contain the fresh water around the city. Sure, above water it looked ugly, and resembled that of an oil rig, but underwater was a freshwater environment that was inside of an ocean environment! It took about 5 years to build.