The featured Ranked Battle stages for May. They didn’t posted them at the Squid Research Lab before.
In case you missed it, these are the featured Ranked Battle stages available this month. Eight stages are available in each mode, and two out of eight stages will be playable in a given two-hour rotation. We anticipate this will allow players to further master and refine their strategies.
— Squid Research Lab
Source: Splatoon’s Tumblr.
…Wanna play? Buy a Switch.
And if you’ve already got yours, click on Splatoon 2 for everything you need to know about the game. 😀