The mine is the place where the vital resource mithril is produced.

 You can obtain mithril by mining or looting other players inside the mithril mine. You can use mithril to exchange for various resources and props in the mine store.
 
 You can unlock each layer in the mine by defeating the guardian monsters. 
 Send your legion to mine mithril or attack other mining players and loot their mines.
 
 The mine collection legion does not occupy the troop queue, so you can send the strongest troops to collect in order to avoid being looted by other players.