Guard Bey (59.8S 88.2W in Ayan Baqur) tells of a moarsman fort nearby on the beach. Located at 60.9S 89.8W. The fort is filled with Tainted Desolation Moarsmen.
Killing all the Moarsmen in the fort causes a few Coral Encrusted Chests to spawn at the top of the Temple. They contain an Extra Large Tainted Egg, use of the chest is on a 6 day timer.
The chests disappear when the Moarsmen respawn after a couple minutes. See Moarsmen on the Shores for more details.