Having seen the movie adaptation directed by Steven Soderbergh, I felt that I knew what to expect from Solaris (1961): a meditation on death and love set in an isolated space station.
Well, I was right on the space station part, at least.
As it turns out, Soderbergh's movie ignored most of the book in order to focus on a single, small aspect of it -- the real main thematic focus of the novel is on exploring our concept of alienness. In a great many science fiction works, the aliens might look or sound totally different from us, but live and act according to motivations that are easily understandable to humans (for a nice visual example, look at how many alien species in Star Trek are only differentiated from humans by the shape of their foreheads and a handful of social quirks). By contrast, the alien species in Solaris, a sentient ocean covering an entire planet, is so mentally and physically different from humans that we might never be able to understand much of anything about it, much less succeed in talking to it. How we cope with the possibility that some subjects are beyond our ability to comprehend them is another major theme in the novel.
Moving on, I was surprised by how short The New Atlantis (1627) by Francis Bacon ended up being (it's only fourteen pages long in Britannica's Great Books of the Western World set). While the book is definitely lousy with the goofy, starry-eyed tone peculiar to all utopian novels, it's still interesting in that its main focus isn't on the minute details of how the utopian nation's society and government work, but on "Salomon's House," an institution devoted to learning, research, and scientific discovery. The way Bacon goes on at length about the scholarly virtues and social benefits of Salomon's House might sound quaint and antiquated when compared with our modern scientific laboratories and research universities, but back when The New Atlantis was first published in 1627 his ideas were far more groundbreaking.