This is the one of the best spot for viewing Mt.Fuji. You can also enjoy Ume and Sakura Garden for spring flowers. There is Toshogu Shrine which enshrined Ieyasu Tokugawa who is the first Shogun of Edo period.
The name of Nihondaira is come from the Japanese myth of Yamatotakerunomikoto (日本武尊). This is where he used Kusanagi Sword to survive from fire attacking from barbarians. After he escape from the fire by his sword, he conquer the eastern area and stand on this Nihondaira Hill.
Official web site:http://www.nihondairakankou.com/