From Final Fantasy XIV Wiki
The Moonfire Faire is the summer event that appeared on September 9, 2013 and will run until October 18th, 2013.
How to Participate
To participate all you need to do is compete in FATEs throughout Eorzea and collect http://xivdb.com/?item/5946/Wet-Bombard-Ash.
|32||Return of the King||Eastern La Noscea|
|15||Return of the King||Eastern Thanalan|
|13||Return of the King||Lower La Noscea|
|11||Return of the King||Central Shroud|
|6||Return of the King||North Shroud|
|5||Return of the King||Middle La Noscea|
|5||Return of the King||Central Thanalan|
Each item can be purchased with http://xivdb.com/?item/5946/Wet-Bombard-Ash at vendors in each of the main cities.