The Parthenon is an ancient building in Athens. It was decorated with many statures. However early in the seventeenth century Lord Elgin removed (ok looted) a number of the statues, that were eventually displayed in the British Museum. The book is a history of how the statues cam to be in London and the various attempts by people to send the statues back to Athens.
Hitchens is a great essayist when he has a cause to support. I say send the Elgin marbles back to Athens! (However, I will look at them in the British museum the next time I am in London.)