Cannes is not at all like tiny Lantosque. It is a large city with two very large cemeteries -- Cimetière du Grand Jas and Cimetière Abadie -- and a crematorium.
If your relative died in the city of Cannes within the last 75 years, write to the mairie (city hall) or directly to the cemeteries or crematotium with the full name and death death date of your ancestor, and request information about the place of burial.
Mairie, 1 place Cornut-Gentille, CS 30140, 06406 CANNES Cedex.
Cimetière du Grand Jas, 205 avenue de Grasse, 06400 CANNES
Cimetière Abadie, 258 avenue Michel Jourdan, 06150 CANNES LA BOCCA
Crématorium, Chemin de la Plaine de Laval, 06150 CANNES LA BOCCA
They usually reply quickly.
Also, here is a link to the website of the cemeteries of Cannes:http://www.cannes.com/index.php?option=com_content&view=...