Chests with treasures are located on many places on Arelith island. Some of them are easy to find, while others are hidden.
Some chests are bashable, and those can be bashed. If it is in your character's nature to bash chests then nothing stops you from doing so. Bashed chests take exactly the same amount of time to respawn as the contents of a chest do.
Most of the content of the chest will be destroyed in the bashing and only coins will be left. Therefore it is always beneficial for adventuring parties to employ services of some lock-picking artist.
These containers can have different forms and names. They serve for selling or donating resources to settlements.