Bartz Klauser and the party arrive at Walse Castle on the back of Tycoon'swind drake to save the Water Crystal, which lies atop the Walse Tower. The king of Walse assures Lenna the Crystal is safe, but a meteorite falls near the tower, and soon after the Water Crystal is destroyed by a raging Garula (implied to have been possessed by Exdeath), and the tower sinks.
In the Merged World, after Exdeath obtains its power, Walse is sucked into the Void.
In Dissidia 012 Final Fantasy, there is a trade material called "Walse Fabric." The item's description mentions it was soaked in sacred water and is constantly damp, likely referring to the water spring where Shiva makes her home.
There is a talking frog in Walse that refers to both a comic based on Final Fantasy III and the game Final Fantasy IV. There is a line in a 4-panel comic done by Yoshida Sensha back when Final Fantasy III for the Famicom was released where frogged party members discuss it not being so bad being a frog, and that they should forgo saving the world and opt living as frogs instead. Someone at Square decided to quote this comic in the next two Final Fantasy games. In Final Fantasy IV the player can interact with frogs in Troia Castle moat. All the frogs in the Japanese version make frog sounds except for one, which says "It's nice being a frog..." This was translated in various ways for English. There is also a secret talking frog in Walse that says the same thing in Japanese. In the Final Fantasy V PlayStation translation this was translated as "frogs are lucky". The GBA translation makes a Kermit the frog reference with "It's easy being green, dig?"