Hiyama, Mountain summit in Fukushima Prefecture, Japan

Mount Hiyama (日山, Hiyama) is a 1,054 m peak on the borders of Nihonmatsu, Katsurao and Namie in Fukushima Prefecture, also called Tennōzan. It is the second-highest summit of the Abukuma Highlands after Mount Ōtakine. At the top stands Hiyama Shrine, whose three shrine buildings face the Tazawa, Mobara and Katsurao districts below.

Originally called Hiyama (桧山) or Tennōzan, the mountain took its present name after the great flood of 1649, when Niwa Mitsushige, lord of Nihonmatsu, had prayers for the sun offered at the summit shrine. The name Hiyama (日山) has been used since then. The summit shrine, Hiyama Jinja, has three halls facing the directions of the Tazawa, Mobara and Katsurao districts below.

At the summit stands Hiyama Shrine, whose three shrine buildings face the directions of the Tazawa, Mobara and Katsurao districts at the foot of the mountain. Each October the Sanbiki Shishimai lion dance is offered there. In late May to early June the summit turns red with blooming yamatsutsuji azaleas.

The hike to the summit takes roughly an hour and is accessible to people with different hiking experience. Visit on clear days to enjoy better views from the top and to make navigation easier along the paths.

In 2000, a photograph of Mount Fuji was taken from the summit, earning Hiyama the title of the northernmost mountain from which Fuji could be photographed. The title later passed to Mount Fumotoyama (Hayama), about 5 km northwest, and in 2016 to Mount Hanatsuka.