Moonlight Canals Mall, on Beckon. I don’t have a map (as I don’t know how to make one) and we are waiting for more shops to be installed and I have one of my own.
That pic includes most of the current mall. Here are the links: Hydronia Boundless
Moonlight Canals Mall
Accessible via: TNT Megahub(Mall portals section), DK Mall, Gyosha Mall, and PS hub Bittula(city portal section)