Made in Abyss, Kujira no Kora wa Sajou ni Utau Recommendations
You are thrown into this unknown world with very different cultures and landscapes that make you want to discover more about the people and how this world affected the society they live in
Watching the first episode of Children of the Whales, I was immediately reminded of Made in Abyss. Both introduce an unfamiliar, mysterious fantasy world that seems to exhibit sentience and have a will of its own. There's also the fact that both feature children as main characters, while still being full of tragedy and bloodshed at times.
Both shows produce a similar feel of to them in terms of the art and story. Heavy fantasy elements and interesting world building. Both shows focus on the violence, tragedy and carnage while being presented in colorful visuals with children as the main characters. Both shows take you on a journey throughout the mysterious worlds while contemplating on the meaning of death and living/survival. If you're looking for something almost as captivating as Made in Abyss, this may be somewhat similar though Made in Abyss has an overall darker tone to it. Both shows are emotional drama.
Both shows aired in 2017 and are based off manga but those are not the reasons I recommend these to those who have seen one and not the other, world building. Both are set in different worlds and manage to build these worlds in a very good way.