After an unsuccessful fishing trip at the pool of Bahia Island, I passed by a strange old man, who "psst!" me from the shadows. Thinking he might be trying to sell pirated DVDs, I went over and talked to him.
It turned out that he was bored, and so was I. (Who wouldn't be when all there is in the game is mindlessly killing monsters? Where are the story plots?!) Anyway, he said:
Did you come here for a vacation? I’m so bored, let me suggest something. You have to find treasures hidden somewhere in Bahia. You only have 10 minutes! If you find all the treasures in record time thrice, I will give you a bonus. There are 10 boxes, and you’ll receive a reward when you find all the boxes. The treasure chests will disappear after a certain time.
So, I paid him 9,000 vis to find 10 treasure boxes. After clicking on 9 of them, the last box was sighted in the audience stand for the arena.
The problem is, of course, there is no way you can access the audience stand unless someone is already fighting in the arena. Is this a bug or just an old man scamming people?