I found Emilie & the Hollow World in the YA section of my local public library but, except for two or three "bad words," I think it would be a better fit in the Children's Section. Emilie and the other human characters aren't quite old enough for romance, although there's a hint that might happen in the future. Perhaps there will be sequels that are a better fit for Young Adults.
Regardless of the intended age group, it's a good book.
I love that it's based on a unique Sci-Fi concept.
Instead of going to outer space or another typical fantasy world, Emilie, who is fleeing from an unpleasant family situation, finds herself on a ship that takes her to the center of the planet Earth.
I did wonder why the force of gravity wasn't different there but, otherwise, that amazing world seemed realistic.
Emily encounters all kinds of dangers and meets people and a variety of
creatures that don't exist on the surface of our planet. She and the
other characters, human or not, seem alive and real and we care what
happens to them. The plot is exciting, but I don't want to give it away so I won't tell any details.
The ending is satisfying, but I hope Marsha Wells goes on to write more books about Emilie because I've come to care about that character.