As part of the
YBCA's "New Anime!" series:
Patema Inverted (サカサマのパテマ) (2013) — A girl who lives in a post-apocalyptic subterranean complex falls down a deep shaft and finds herself in a world where everything is upside-down.
I was of course reminded of this passage in
Alice's Adventures in Wonderland:
"I wonder if I shall fall right through the earth! How funny it'll seem to come out among the people that walk with their heads downwards! The Antipathies, I think—" (she was rather glad that there was no one listening, this time, as it didn't sound at all the right word) "—but I shall have to ask them what the name of the country is, you know. Please, Ma'am, is this New Zealand? Or Australia?"
I wouldn't be at all surprised to learn that this was in fact the inspiration for the
Patema story.