Very burnt out but still trying to make stuff.

This is a World Portal, a creation of both Valkyrie and Human ingenuity.

World Portals are used to get in and out of Valksung (the Valkyries city in the sky,) and are pretty much the only feasible way to enter.
It runs off of sunlight, as well as having a special way to be opened or closed. A square like device called a “tuner” is the only way to open or close one of these, and requires white essence or Tyxes essence to function.

This one in particular is on Valksung, and leads to the ground world city, Atlas.