Gambler's Lucky Keys

I was just curious where they drop the most frequent at? I would like to try and grab 15 of them in the near future….Thanks!

Heroic Forgotten Dungeon

Thanks Khego!

I recently got one of these keys in the normal Forgotten Dungeon. Where is the chest located to use this key?

Just did a simple search and found my answer (doh). Wen Down 1.