Bront's Forums

No, I'm not talking about drops, locked chests, or even end dungeon chests.

There's some special treasure locations in Nightfall, and you can loot it aproximately once a month per character.  I haven't looted them all yet, but supposedly you can make up to 20 plat per looting if you loot all them. 

I looted the 2 on Istan earlier today, and found 2 gold items (which is odd and good in a beginning area).  Made almost 500 gold off the two, and got a good inscription to hold on to for a shield for my warrior.

I'll explain more, but the Wiki entry does it better.

Guild Wars Wiki entry on Treasure

No, actualy, you can farm them, but you have to let them rest for a month or more, and if you don't, the timer resets.

Or at least that's the current belief.

They haven't changed it since Nightfall came out...

There are faster ways to make money, but the golds are nice.  I need to loot them with my mesmer, I was busy working on primary quests and such (Just got to Vabbi)