One of the best books I've ever read. There isn't some crazy conflict, just scientists exploring something for the most part. Plus there are three more that show what's actually happening.

If you remember oumoaoa, that thing that came into our system from interstellar space and was rotating like it would if it was hollow inside and needed to provide centrifugal gravity... You'll see how everyone who read Rama was kinda secretly bugging out.

I also recommend Childhood's End, also by Clarke and imo his coolest book. It's short and seriously great, one of the best endings of anything I've read.