Capsule: There are two very different Allison Islands -- north and south. Aqua, a modernist community of mid-rise condos and 46 homes on South Allison Island (shown above), is surrounded on three sides by nearly a half-mile of waterfront. North Allison Island, in dramatic contrast, is a long-established private island community set in a lush tropical setting in which the homes are separated by a palm tree-lined median strip.