 The nearest land mass from Grand Cayman is the Canarreos Archipelago (about 150 miles away), whereas the nearest from the easternmost island Cayman Brac is the Jardines de la Reina archipelago (about 100 miles away) - both of which are part of Cuba.All three islands were formed by large coral heads covering submerged ice age peaks of western extensions of the Cuban Sierra Maestra range and are mostly flat.One notable exception to this is The Bluff on Cayman Brac's eastern part, which rises to above sea level, the highest point on the islands.