So title says it basically. How will zones be 'Seperated' from the others?

Will it be like in other MMO's where there are only 1/2 entrances to the place and the rest is all blocked off with mountains, and will there loading screens when going from one place to the other? Or will it be open all the way? (surely there will be some mountains, but not a ridiculous amount of it just to seperate zones from each other.)

Personally I've never liked whole zones being blocked off by mountains. It feels extremely unrealistic. What do you think what would be used or what would you like to see instead?

I like the use of mountains and other natural barriers, especially over the use of loading screens. I only want to see a loading screen if I fast travel, or enter a specific building or city.

I would like to be able to get there many different ways. There could be a main road or two in and out, and you could get in other ways by traveling through the wilderness. Mountains and other natural barriers could be present to block off necessary things.