Mount Nantai, Sacred mountain summit in Nikko National Park, Japan

Mount Nantai is an andesite stratovolcano standing on the north shore of Lake Chuzenji in Tochigi Prefecture, reaching 2,486 meters above sea level. Its cone-shaped peak dominates the forested slopes and lakeshore below, shaping the landscape of Nikko National Park.

Buddhist monk Shodo Shonin climbed to the top in the 8th century, turning it into an important religious site. Since then, the peak has drawn pilgrims from across Japan and contributes to the World Heritage designation of the Shrines and Temples of Nikko.

The summit is considered the sacred body of the deity enshrined at Futarasan Shrine, and pilgrims have climbed here for centuries to pray. At the top, a small shrine stands where hikers still leave coins and prayers today.

The climbing season runs from 25 April to 11 November, extended from the former 5 May–25 October window in 2019. Hikers pay the entrance fee at Futarasan Shrine's Chugushi on the south shore of Lake Chuzenji and receive a safety charm. The ascent takes about 3 hours 50 minutes and the descent 2 hours 30 minutes; between the third and fourth stations the route follows a road for roughly 30 minutes. Tobu buses from Tobu Nikko Station reach Chugushi in about 53 minutes.

The summit shrine's stone torii toppled in the 2011 Tohoku earthquake. A local man funded a hinoki cypress replacement, carried up in pieces and reassembled on 13 October 2012. That same year a 3.5 m iron sword donated from Yuki in 1877 was found snapped by corrosion; a stainless steel sword replaced it.