Large seed, tan in color, 6" length, 4" height, 2 " thick. The skin feels like leather. It appears it has started to sprout. When gently squeezed it feels spongy. I though it might be a pod with a bunch of seeds inside, but I think this is a single seed. I pictured it with a 750ml bottle of Olive Oil to give you a true perspective on how large this thing is.
I found it on the beach. Most likely traveled by sea.