VJ, Thank you for your service. Where would you like to look? Let us first start with your family tree. I call this "Shack Your Family Tree, Maybe A Pirate Will Fall Out. No, not one pirate named Melancon. Iberia Parish is full of Stories. Jefferson Island has had a lot of people looking for Lafitte treasure. In 1921 several gold cones were found. 1928 at a place called "Voodoo Land, $40.000 in English, French and Mexican gold and silver, was found. In 1933 Spanish and Mexican gold and silver coins were found. I am told these sites are on private land. Marsh Island, treasure from a wrecked ship found on Padre Island, Texas, was buried by the Spanish for safe keeping, until another ship could be sent to retrieve it. State property, can't dig that. 1952 a "Bushel of Coins" was found on Jefferson Island.
Hubertville, a section of Jeanerette, has a story about a planter who buried all of his valuables and joined the Confederate Army and never returned. Avery Island is said to be the first Indian settlement in Louisiana. There are more Indian sites. Saint Gabrial, The Houmas House Plantation, roomer-ed to have buried treasure there. There is a lot of history there.
The thing is I could go on and on about just your Parish, I you want to know about a specific treasure in area, please ask, tell me what your are using. Good Luck.