Started reading Sword Art Online, and since it's my first time reading novels in Japanese, the first paragraph is already making me ask questions on Stack :P
I get the basic idea of the sentence, but the grammar coupled with unusual punctuation trips me up. What's going on in the middle part between the two commas? I'm not sure how it works, given that there are no particles or anything attached to キロメートル and it doesn't seem like the topic-wa relates to the rest of the sentence in any way, only to the part within the commas.
Also, if somebody knows what もあった is supposed to be in this context, I'd be happy to know.