Location:  The Ichishi District in Ise Province.

Features:  Situated in mountainous terrain at an elevation of 312 meters to the west of the town of Ōazaka.  The castle grounds were divided into northern and southern portions, with the northern structure known as Shiinoki Castle and the southern structure referred to as Hakumai Castle.   Shiinoki was the larger of the two with an elevated base 70 meters square surrounded by a complex array of neck ditches and mounds.

History:  Originally built in 1335 by Kitabatake Chikafusa in the southern part of Ise Province.  In the Sengoku era, Azaka Castle served as a key base of operations for the Kitabatake clan to defend against threats from enemies in northern Ise.  In 1567, Ōmiya Ganninsai, lord of Azaka, repelled three attempts to capture the castle by Oda forces under the command of Takigawa Kazumasu, a senior retainer of Nobunaga.  Two years later, the Oda laid siege to Hakumai Castle and issued a notice of surrender to Ganninsai and his son, Dainojō, only to be rejected by the defenders.  An expert archer, Dainojō struck Toyotomi Hideyoshi in the thigh with an arrow, and temporarily held the advantage until a retainer named Endō 源六郎 colluded with the Oda by pouring water on the gun powder stored in the castle to undermine the resolve of the defenders.  This led Ganninsai to relinquish the castle in exchange for sparing the lives of his soldiers.