The two other reviewers already did an excellent job reviewing this TV part trilogie based on Jean-Claude Izzo's trilogy "Total Chaos", "Chourmo" and "Solea" which I've just read this winter and can highly recommend to read. The translator did a great job...it's such a riveting read.
Being a fan of Alain Delon since I watched "Plein soleil" aka "Purple Noon" (still my favorite of more than 40 Delon films that I have watched), I finally watched "Frank Riva" and "Fabio Montale" mainly to complete my Alain Delon collection last year.
And while watching "Fabio Montale" I fell head-over-heels in love with Les Calanques, the gorgeous landscape east of Marseille where Fabio Montale lives in his parents' home (both of them deceased).
So for me Marseille and Les Calanques, the small and deep coves between Marseille and Cassis, are the true star of this TV trilogy. The cinematographer did an incredible job and of course Alain Delon is as always simply wonderful to watch.