There's an art to writing them, because the marvels still have to engage with and interact with the viewpoint character. Colorless and drab though that character may be. And the character has to be given a lively enough motive to get through the story. True, if you make it dramatic enough the motive can be "Run for my life!" often, and if curious enough, "Whatever is that?" but something's got to string them together into a story. In the Alice books, she wants to get into the garden and to become a queen respectively. In the Wonderful Wizard of Oz, Dorothy wants to get home. (In the movie, they tried to give her a character arc. Alas, they tried to make it that she did not want to go home up front. But she still is sent on the Yellow Brick Road to find the Wizard to get home. It's not much use thinking of a thing until you think it through. The Munchkins could have not known whether she could stay, and told her she should check with the wizard to see if she needed permission.)
But the marvels need to be dramatic or wonderful and interactive, even the overriding motive will get the character through teh scene. A rainbow bridge is lovely, but arguing with the guardian produces incident. Or even finding the bridge rather slippery. (Hey, things get wet when it rains.) Alice does not merely talk with those she meets, she gets into arguments with them. Dorothy has to work out how to escape the poppy fields -- not by a convenient snow fall, but with the advice of the Queen of Mice. Which can be fun if the original inspiration was the bright and sparkly setting and not so much conflict.