Okinawa City. The population distribution is approximately 120,000 in northern Okinawa, 590,000 in central Okinawa and 540,000 in southern Okinawa. It has a high population density of 1,014.93 people per km2. During the Meiji Period, Okinawan ethnic identity, tradition, culture and language were suppressed by the Meiji government, which sought to assimilate the Okinawans as Japanese (Yamato). Many ethnic Japanese have since migrated to Okinawa. The modern inhabitants of Okinawa are mainly ethnic Okinawan, Japanese, half Japanese and mixed. Five times as many Okinawans reach 100 years old compared to the rest of Japan. The Okinawan diet consists of low-fat, low-salt foods, such as whole fruits and vegetables, legumes, tofu, and seaweed. Okinawans are known for their longevity. This particular island is a so-called Blue Zone, an area where the people live longer than most others elsewhere in the world. there were 34.7 centenarians for every 100,000 inhabitants, which is the highest ratio worldwide. Possible explanations are diet, low-stress lifestyle, caring community, activity, and spirituality of the inhabitants of the island. Geography Okinawa is the fifth largest island of Japan. The island has an area of . The coastline is long. The straight-line distance is about from north to south. Okinawa is in the northeastern end of Okinawa Prefecture. Since 1972 over of land reclamation has been conducted. It is roughly south of the main island of Kyushu. Okinawa is connected to nearby islands near a land bridge: Katsuren Peninsula is connected via the Mid-Sea Road to Henza Island, Miyagi Island, Ikei Island, and Hamahiga Island. Similarly, from the Motobu Peninsula on the northwestern side, all of Sesoko-jima plus Yagaji Island and Kōri-jima are connected by bridges. Okinawa Island has several beaches such as Manza Beach, Emerald Beach, Okuma Beach, Zanpa Beach, Moon Beach and Sunset Beach (Chatan-cho). Mount Omoto, at , is the highest mountain in Okinawa, with Mount Yonaha being the second highest. The Motobu Peninsula in the north has limestone layers and karst development. In the center and south is mainly a Ryukyu limestone layer and mudstone. The topography is flat, there are few hills over with very few rivers. The subtropical rains accelerate erosion so there are many drainages and uvala. The southern end of the island consists of uplifted coral reef, whereas the northern half has proportionally more igneous rock. The easily eroded limestone of the south has many caves, the most famous of which