Using DE for a city

Question

Why use why use elles vont de Cannes pour le festival du film. I used A and got it wrong

Cécile Janty-Davies · Accepted Answer

Hi Neil,
The sentence was -
They are going to Cannes for the film festival = Elles vont à Cannes pour le festival du film

aller à = to go to 
venir de = to come from

So à is correct.
Hope this helps!

Jim Jones · Answer

Hi Neil,You would be correct if you had written "à Cannes" but your post suggests that you wrote "a Cannes".Is this the simple answer to your query because on the face of it you are correct provided you wrote à not a?Jim

Crush Lastname · Answer

ok. I clicked the wrong answer. Understood.

Crush Lastname · Answer

Elles vont à Cannes pour le festival du film.My answer was marked wrong for not choosing "a la". Nothing in this article says why it would be La Cannes. Is that the name of the place and how were we to know there was an article?