is the highest point on

Rebun Island is an island in the Sea of Japan off the northwestern tip of Hokkaidō, Japan. The island sits off the coast of Hokkaidō. Rebun stretches from north to south and from east to west. The island covers approximately . Rebun Island is located ...

in Rebun,

Hokkaidō is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The la ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. The mountain consists of marine

sedimentary Sedimentary rocks are types of rock (geology), rock that are formed by the accumulation or deposition of mineral or organic matter, organic particles at Earth#Surface, Earth's surface, followed by cementation (geology), cementation. Sedimentati ...

rocks from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

period, 149–97 million years ago.

Climbing route

The trailhead for the Mount Rebun hike is in Nairo. It is a 3-hour hike with no water available. The trail first passes through fields of ''sasa-no-ha'' before entering a forest of pine and birch. The peak rises above the forest to grant an unobstructed view of the entire island.

References

Rebun {{Hokkaido-geo-stub