The Kansai region is a cultural center and the historical heart of Japan, with 11% of the nation's land area and 22,757,897 residents as of 2010. The Osaka Plain with the cities of Osaka and Kyoto forms the core of the region. From there the Kansai area stretches west along the Seto Inland Sea towards Kobe and Himeji, and east encompassing Lake Biwa, Japan's largest freshwater lake. In the north, the region is bordered by the Sea of Japan, to the south by the Kii Peninsula and the Pacific Ocean, and to the east by the Ibuki Mountains and Ise Bay. Four of Japan's national parks lie within its borders, in whole or in part. The area also contains six of the seven top prefectures in terms of national treasures. Other geographical features include Amanohashidate in Kyoto Prefecture and Awaji Island in Hyōgo.