Barrel

Barrels spawn in Tyras camp, in the Mining Camp, and in the abandoned apple yard south of the Tree Gnome Stronghold.

A barrel is used:
 * During the Regicide quest as a component in making a bomb needed to destroy Tyras camp.
 * During the Mourning's Ends Part I quest to make a poison.
 * During the Tourist Trap quest to rescue Ana.

The barrels are mainly used in the quests to be filled up with coal tar making a Barrel of coal-tar or rescue NPCs, as such in the Tourist Trap quest.

Barrels have no further use in the game.

Trivia

 * If you examine a barrel in front of the Varrock castle, it reads "RuneScape, land of a thousand barrels." This relates to Minnesota's state motto, "Minnesota, land of ten thousand lakes."
 * It might also refer to Thailand, said by many to be "the land of a thousand smiles".
 * There is a barrel containing water in Wilderness.