The London Eye Mystery, by Siobhan Dowd. While it didn't really provide much background about London (beyond a description of how the famous London Eye works), it was an entertaining story.
Ted has a unique way of approaching things. His Asperger's Syndrome causes him to analyze things more thoroughly than others and miss cues that others pick up easily. So, when his cousin, Salim, goes up in a sealed London Eye pod and fails to exit when the pod returns to the ground, Ted immediately begins to process all the options and seeks to ferret out the truth. Together with his sister, Kat, he follows clues all over London and solves the puzzle of what happened.
I enjoyed the quirkiness of the narrator. It was a pleasant little read. Kids who are getting ready to visit London, and especially the London Eye, will enjoy immersing themselves in this story first. It would be interesting to see if young people who have Asperger's feel a kinship with the narrator.