For those who have not completed games in the Xenoblade Chronicles series, this page contains spoilers regarding the plot. Discretion is advised.
Ancient Machines are bosses in Xenoblade Chronicles. They are fought at level 8 in the Colony 9 area. Upon reaching the Cylinder Hangar, the party is forced to fight two of them to continue the story. The first Ancient Machine on the left has a higher attack strength while the second one has a higher ether power.
They are the first bosses found in the game, Battle of Sword Valley prologue, prior to the events of Xenoblade Chronicles, not taking into account.