Zeno's Palace exact location is unknown but it resides above a huge jellyfish that is located in between golden clouds and what appears to be outer space. It is also a separate location from the 12 universes.
The palace where Zeno lives is located on the top of a huge jellyfish and it is in the shape of the kanji "全" that means "all". It also keeps floating. Around the castle there are twelve floating rocks that each has a Universe above them.