My Experience with this World:
My experience the Underland Chronicles by Suzanne Collins actually predates my reading of the books. My mom read them, you see, and thought they were good, but they didn't really interest me. However while we were plotting together, it just kept coming up as an example - usually when we were plotting my Rizkaland Legends.
So, at long last, I hunted them down and started reading.
I read the first three pretty quickly, and I loved them, but for some reason I had trouble getting through book four and book five went back to the library virtually untouched. I have no plans of getting it back out. I read enough of it to know what happens and that's good enough for me.
Underland itself is about as old as earth itself, since it IS part of earth. However, the human colony was established when the Duke of Sandwich marched a group of men down, made alliances with the inhabitants, and started building.
I don't think that a map exists of Underland, and I've definitely never seen one, so I have no idea what it looks like. I know there's Regalia, the human capitol, which is built mostly of stone. Beyond the city there are all sorts of strange places and caves and underground water systems. There's even a frightful forest full of carnivorous plants.
Really, this isn't the friendliest vacation spot.
Peoples and Culture:
There are humans down in the Underlands. They mostly live in the capitol city of Regalia, but there are other colonies, such as the Fount, and even a few loners who somehow manage to survive on their own. Because they live underground where there is no sun, they have pale skin, silver hair, and violet eyes. Humans who fall from the world above are called Overlanders.
Then there are the rats (or Gnawers, as they're called down there), who are mean, vicious little creatures. Wait, did I say little. I'm sorry, I didn't mean to deceive you. All of the non-human creatures down in Underland are HUGE! But, anyways, the rats are mean creatures, for the most part, they don't like the humans, consider them intruders. The humans don't like the rats either. There are a few nice ones, such as Ripred.
And then there are bats, or fliers. They are close friends with the humans, flying them around. Some of them form close friendships, and will have a special bonding ceremony in which they basically declare that they'll risk their lives for the other no mater what.
And there are the Crawlers, or giant cockroaches. They're very resilient, but looked down on the other peoples.
What I like about this world:
The realism of this world is quite unique. Most books that I've read that involve a world under the surface of the world are magical realms and have a sun and a moon and other delightful things like that. But Underland is real. There is no sun. It's dark. It's scary.
What I don't like:
Suzanne Collins is best known for her Hunger Games trilogy, and there are themes that both books share. I'm not a huge fan of books where everyone dies. That's a big reason why I haven't read the last book of either series.
Also the prophesies, a major plot devise in this novel, get old after a while, though the one in book four is cleverly done.
What I learned from this world:
As I mentioned before, this book was one of my mom's big "examples" when we would talk plot about my books. It primarily influenced my Rizkaland Legends.
Also when I read it myself, I found it influencing my own book The New Division, (which, interestingly, a prequel to the Legends, in a way) especially when it came to the character Liya, the grandmother of two of the main characters.