Nikaidō (二階堂) is the name of one of the administrative units ("towns", chō or machi) of Kamakura, a city located in Kanagawa, Japan, about 50 km south-south-west of Tokyo. Nikaidō lies immediately to the east of Nishi Mikado and Yukinoshita, and used to be called Higashi Mikado. The name is still sometimes used. In it lie famous temples and shrines like Zuisen-ji, Egara Tenjinsha, Kamakura-gū and Kakuon-ji. It's in Nikaidō that first Kamakura shogun Minamoto no Yoritomo built Yōfuku-ji (永福寺?), one of his most important temples. It was probably part, together with Yukinoshita, of the Ōkura Valley that gave its name to the Ōkura Bakufu, Yoritomo's first government.
After his wars with the Taira clan and Ōshū's Fujiwara clan, in 1189 shogun Yoritomo founded a temple called Yōfuku-ji to comfort the souls of the samurai that had died in them. The temple was erected in a location next to today's Kamakura-gū. Its main hall was a two-story building called Nikaidō, which was copied from Chuson-ji's Daichō-in Nikaidō (大寿院二階堂?) in Hiraizumi, a building the shogun had greatly admired. In time, that famous building gave its name to the entire area where it stood. According to another theory, however, the name comes from that of an important clan vassal of the Minamoto, also called Nikaidō, because that's where the clan's mansion used to stand.