D-Day

The Nazis weren't exactly expecting the attack to come from there, so it was a good place to launch a surprise attack.

It was a north german beach and they were expecting the attack in a beach on the west

Bombers in Britain could reach Normandy - with bombs (to crush bunkers and german defenses) and paratroopers (13 000). They would not have reached Greece 8b25b1.jpg (click to show)
In addition when you look at what happened in Italy (a such mountainous country) - it doesn't sound a good idea

the canadians helped a lot on d day, they had their own beach that they invaded, it was called Juno