My French is very limited - probably straddling the border of upper beginner or lower intermediate - but I read through Barjavel's La Nuit Des Temps and it was fuckin awesome.
Nice! It is a great book and, if one excepts Jules Verne, it also was the very first French science fiction author I ever read. The book made a huge impression on me too. So much so that I then read all of what Barjavel wrote, SF or otherwise.
BTW, I would not consider anyone capable of reading a novel in a foreign language a beginner, even a 'upper' one. That too is awesome, if I dare say so ;)