I decided to go on a mini hike in my backyard and finally found the ruins of Kinugasa castle. All that is left is the foundation stones. It was build in 1063 Heian period and fell during the battle of Kinugasa in 1187. I can’t find much info on it.
According to Wikipedia “During the Heian period, local warlord Muraoka Tamemichi established Kinugasa Castle in 1063. He became the ancestor of the Miura clan, which subsequently dominated eastern Sagami Province for the next several hundred years. The Miura clan supported Minamoto no Yoritomo in the foundation of the Kamakura shogunate, but were later annihilated by Hōjō Tokiyori in 1247.”
Also came across a small Inari Fox Shrine.