A man-made island consisting of six artificial hills built on a series of geodesic domes of varying sizes is planned off the shore of Istanbul, Turkey. The island would house 300,000 people in low-rise residential units built horizontally around the dome on a 3-D grid, with commercial space in the interior. The domes would surround a central valley used for recreation and parks. Each dome will rise atop a mega-structural sphere -- a system that would "maximize energy and structural efficiency" -- creating a net-positive energy structure, according to New York-based Studio Dror.