Season 2 hard mode says 210/270. 21 provinces with 10 levels each gives us the 210. Only 3 more provinces are visible, but 60 more levels are required. Either provinces 22-24 contain 20 levels each (highy unlikely) or there are 3 provinces under the maelstrom.
Or the quest is a misdirection .
[edited for spelling]
I think that with theese atlantean something is fishy… 
There are three more. When the last three are completed.
This circular underwater spacestation will probably contain the three final sets of stages.
Possibly a giant octopus could be the final boss.
The Kraken!
20,000 leagues
Huh, I always thought it was a janky toilet of some kind.
I only recently noticed that the Atlantean thingamabob has been gradually rising out of the water with each month. So, excellent hypothesis, well done!