The OP is clearly asking for a defined, separate PvP area. Likely one that would clearly notify players upon attempt to enter that they're entering a PvP area. Even the dueling circle does this. Go to the Wolves' Den, and step over the glowing outline and you'll see a notification. I'd imagine an area you'd have to zone into manually would have a pop up, not unlike when zones had instances. There would be no necessary-for-PvE content there, so no one would be missing out on any PvE content by refusing to go in.

An alternative method, unless this has changed since my time with the game, would be faction related gear a la Blade & Soul. Wear the gear, and you're consenting to the possibility of engagement. Don't want to be bothered? Don't wear it. SE could accomplish this with Status settings too.

No one is trying to transform the game into something it isn't. In fairness, I'm not even crazy about open world PvP myself (and simply because I spend a LOT of time using gpose or scouting locations for my video work), but it'd be nice if PvPers got even just a little bit more sometimes without public outcry.