Strata

Über

Strata is a science fiction novel by Terry Pratchett. Published in 1981, it is one of Pratchett's first novels and one of only two purely science fiction novels he has written, the other being The Dark Side of the Sun.
Although it takes place in a different fictional universe and is more science fiction than fantasy, it could be said to be a kind of precursor to the Discworld novels, as it also features a flat Earth similar to the Discworld. It has been called a "preconsideration" of Discworld, though the plot and characters are modelled on the novel Ringworld by Larry Niven.