there is a portal in the very center of the map; between the archons and the elementals. Stand on that for a bit.
To get out; you gotta stand on the portal out for a while also.
The treasure chest is not an "end of the game boss". He is intended to be fought whenever you are strong enough to beat him; and the reward is a lot of gold. Not really a LOT, but more than you would earn doing almost anything else.
While in the center; you are worth double bounty to enemy players. Keep in mind that it takes a while to get out also; so it is a great place to kill opponents after they defeat the chest and are weakened.
