Ever heard of an icaco, or (in English), coco plum or paradise plum? It's a tropical fruit that grows on trees as close as 30 feet from the ocean. The closer to the water, the sweeter the fruit.
The tree is native to the tropical parts of the Americas, especially the Caribbean.
People eat them raw, cooked or made into jam.
The seed of the icaco is 21% oil, and some people burn them for light.