Strongboxes

Special chests, called Strongboxes, can be found throughout Path of Exile. Unlike ordinary chests, Strongboxes are protected by monsters that must be defeated before the Strongbox will relinquish its treasures. Although Strongboxes are not technically items, they do share some special traits in common with many of Path of Exile's items. Specifically, Strongboxes have mods and, like items, these mods can be changed with the use of currency. There are several different kinds of Strongbox to find, each

It is often worth carrying some currency items with you, so you can modify any strongboxes you happen to come across. The difference between a normal Strongbox and a well-crafted magic Strongbox can be quite significant.