The Lukunai Expedition was a Second Age expedition to reach the old capitol of the Marcon Alliance by way of the Nara River. The exact dates of the expedition are unknown, though "about a century before the Messer Expedition" (A.Y. 2185) is often given as a date.
According to historical sources, the Lukunai Expedition made it all the way to Lake Bentika. However, the earliest written account dates to A.Y. 2397, over two centuries after the Messer Expedition, from a biography on Nate Messer. Most historians now agree that the Lukunai Expedition never happened.