The YGGDRASIL space station -also known as Archology XII- is a huge
structure housing the city of ASGARD. The tree used as base was
nano-treated during 100 years, enhancing its growth to its maximum and
protecting it against deep space. The nano-treatment also increased
its photosynthesis and the flow of energy inside its giant leaves
providing a natural energy shield to the YGGDRASIL station.
It is the home of the third fleet and its capital ship, the ODIN. The giant freighter SLEIPNIR is permanently assigned to the city.
Credit to Andrew Colunga for the spheres.