ABANDONED. YA action fantasy with a chase through a cliff city

[Ling]

I must have borrowed this action-fantasy YA book from the library in the early 2000s, and lately I've been recalling a scene from it, but can't remember its title for the life of me!

So there's this city/town/bustling place with inhabitants that's built into the side of a sheer (red?) cliff, so it is a city you kinda move vertically around in. And someone is getting chased through this city that's totally foreign to her, and then there's something about crows and/or flying into the red sun...

I'm sorry details are sparse + might be off (I might have mixed stuff from other books into it), but the cliff city was strongly imprinted on my memories so that's really the key. Please tell me it isn't just something I dreamt up! (although that'd be pretty cool too.) 

[Lobstergirl, au gratin]

Wai, are you still looking for this or did you find it?

[Nachelle]

in "The Merlin Conspiracy", the main character is chased through a vertical city that is unknown to him, and there is a powerful sun that is talked about.

[Nachelle]

I forgot to add the author; it's by Diana Wynne Jones.

[Rainbowheart]

The Merlin Conspiracy for the link.

[Lobstergirl, au gratin]

Lobstergirl wrote: "Wai, are you still looking for this or did you find it?"

No response in 2 years. Moving to Abandoned.