Yakashima is a stratovolcanic archipelago of 521 islands. The 3 largest are Meitochi, Botonishi and Engishima, which make up the majority of Yakashima's land area. Yakashima's population of 36.9 million, making it the 37th largest in the world. 6.7 million people live in the Sentomachi area, making it the 39th largest city in the world