Treasure chest

In Assassin's Creed II
The Treasure Chests appear as shiny boxes. The chests are existent in all Assassin's Creed II cities (usually hidden on balconies or on rooftops). If the player can find them he or she will receive some florins.

Chests in cities are protected by either a single guard, or a team of up to four guards.

The Codex Pages and Chest 'buildings' are referred to as banks in the Animus Database, but they do bear a small resemblance to Giovanni Auditore's office, albeit much smaller.

Rebecca states that although all families own banks, most of these banks are owned by the Pazzi family and that breaking into them (By silencing the guards) will be worth your time.

Banks will always contain 2 chests or one codex page. Also, the amount of money you get from the chest varies greatly, from rewards of 100 to over 1000 florins.

If a treasure icon is blinking dimly, that means the treasure chest is located either above or below your current altitude.

At the art dealer in each city, one can buy treasure maps which show the locations of treasures in that city.

In Assassin's Creed Brotherhood
In Assassin's Creed Brotherhood treasure chests act much like the way they did in Assassin's Creed II but now they not only contain florins, but necklaces and rings as well.

Armed Disputes and Battles
It is possible, in Florence and Tuscany, to create a small battle via banks. To do this the player needs to come across a Pazzi owned bank (the soldiers are dressed in Pazzi red, not Medici yellow), and either attract Medici guards to the Pazzi ones or attract the Pazzi guards to a Medici patrol (by angering the guards and getting them to follow the player). Just lead them to each other and watch them brawl. On a rare occurrence, a guard may still target you rather than his other enemies, just silence him and keep your distance. If you want to have even more fun; Invite a few Mercenaries or Thieves into the brawl, or even better throw a few coins into the midst of the battle and watch the Civilians get massacred.

Trivia

 * If you decide to invest in a well for your Villa Auditore, you will notice that you can actually go down the well and survive, unlike others in Florence and their cities, beneath the well there will be 2 chests, and if you invest in a mine just north of the city wall, you can go into the mine, there will be 2 chests of florins waiting for you to collect. There will also be 2 chests in Ezio's room, the top floor of the villa. These chests, being rare, unfortunately only contain 200-600 florins.
 * The amount of florins in each chest increase with every new city the player travels to, probably due to the increasing cost of weapons and armor.