How to build an Alliance Territory?

Does anyone know how to use the Alliance Territory? (It was added in the latest update)

Anyone care to explain? I don't really get this part

Basically the alliance territory is a location within which you gain additional buffs.

Also, by being near to each other, other alliance-type of events occur more easily: - Dark Knight event, alliance teammates can reinforce each other, thereby raising the points gained.

Also, via turrets built within alliance territory, you gain additional attack on incoming armies.

You also can build an Alliance SuperMine, basically a large resource tile that you cannot be attacked in while gathering, and many alliance members can gather from it.

Additionally theres an Alliance Storehouse, allows for many players to store their resources for safekeeping.