On a sunny Sunday afternoon, a little boy and his parents ride their bicycles to the mangrove forest, where they have a good time observing nature. Through the dialogue between the little boy and his parents, the story reveals the rich ecology of mangroves and the appearances of animals and plants. The author describes nature in close detail, which allows us not only to observe the fiddler crabs and mudskipper spots but to explore the wider mysteries of the wetland.