i think it would look nice at the location that’s right in front of the beach! (the bottom one aha) - with the other location, you might have a harder time trying to make it look natural since it might look randomly placed and it’ll kind of be right in the middle of things which could be an eyesore.
but with the other location, i think it’d be really easy to make it look natural with some trees and other decorations! and being able to access the beach behind it, too, definitely could help! i think a lil beachy rock garden could be really cute and plus, it’d be near the edge of your island, so it wouldn’t be gob-smack in the middle of anything aha,, hope this helps at all >_<