Board Thread:Off-topic/@comment-26573135-20151020201401/@comment-26182384-20151024191033

(I know the solution! There is a geological formation called ria in which the sea flows into the mainland instead of doing opposite. It is defined as "a long, narrow inlet formed by the partial submergence of a river valley".)

Larimar: *chasing some Gem-fish* Come here, yummy fishes *the fish go to the coast* Where are you going? What is that... mount *looks at the island suspiciously* Let's investigate...