The Narrow Road to the Deep North, by Richard Flanagan
Although its subject matter makes it heavy going, there's no doubt that every fan of literature should read this. Flanagan's novel won the 2014 Booker Prize, and most of it is truly excellent.
The core of the book is set in the Siamese jungle in 1943, and describes in remorseless, horrendous detail the forced labour of Australian prisoners of war during the construction of the Death Railway. Flanagan does about as good a job as anyone could of conveying the relentless misery and suffering inflicted on a few of the hundreds of thousands of victims (mostly Australian, British and Dutch prisoners, along with many more local civilians).