Ashran is a level 100 instanced cross-realm "end game" world PvP zone

It is located on the eatern coast of Tanaan Jungle. A staging area near the dark portal that the Horde and the Alliance wants to control.

This has faction bases on it and a variety of different hotspots, a lot of different points of interests the factions want to control.

What separates this from previous PvP zones, is that it is a PvP sanbox that is persistent and continues on all the time. Meaning it does not have a start and finish. This is more like a timeless isle of PvP. All the objectives there are all PvP oriented.

You are free to go in there and do whatever you want to do. It is a lot like the original Alter Valley.

You can do several things such as taking over the mine to supply the team or build a siege vehicle to take out the enemy base, take over a tower etc.

Ashran uses cross-realm technology so it will be a good balance.

There will be tons of points of interest around leading to constant nonstop action.  

You can build and commander siege vecicles. Some of them takes even multiple days to build. You might gather some materials on one day and continue your progress on the next day and eventually build your machine of mighty destruction and have a rampage on your enemies for a while.

You can also commander the Iron Horde vehicles that are lying around since they had a presence there as well.

If you want a full Guide of Ashran PvP World, click here (external link to wowpedia)