Mount Rishiri is a quaternary

Quaternary

The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...

 stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 located off the coast of Hokkaidō

Hokkaido

, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

, Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 in the Sea of Japan

Sea of Japan

The Sea of Japan is a marginal sea of the western Pacific Ocean, between the Asian mainland, the Japanese archipelago and Sakhalin. It is bordered by Japan, North Korea, Russia and South Korea. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific...

. The extinct volcano rises out of the sea forming Rishiri Island

Rishiri Island

rises out of the Sea of Japan off the coast of Hokkaidō, Japan. The island is formed by the cone-shaped extinct volcanic peak of Mount Rishiri. Along with Rebun and the coastal area of Sarobetsu, Rishiri forms the Rishiri-Rebun-Sarobetsu National Park. The main industries of Rishiri are tourism and...

. Because its cone shape resembles Mount Fuji

Mount Fuji

is the highest mountain in Japan at . An active stratovolcano that last erupted in 1707–08, Mount Fuji lies about south-west of Tokyo, and can be seen from there on a clear day. Mount Fuji's exceptionally symmetrical cone is a well-known symbol of Japan and it is frequently depicted in art and...

 it is sometimes referred to as Rishiri Fuji. It is one of the 100 famous mountains in Japan.

Mount Rishiri's opening festival is held annually on July 2 and July 3. This festival officially opens the climbing season.

Geology

Mount Rishiri is made up of alkali and non-alkali mafic

Mafic

Mafic is an adjective describing a silicate mineral or rock that is rich in magnesium and iron; the term is a portmanteau of the words "magnesium" and "ferric". Most mafic minerals are dark in color and the relative density is greater than 3. Common rock-forming mafic minerals include olivine,...

 volcanic rock dating from the Late Pleistocene

Late Pleistocene

The Late Pleistocene is a stage of the Pleistocene Epoch. The beginning of the stage is defined by the base of the Eemian interglacial phase before the final glacial episode of the Pleistocene 126,000 ± 5,000 years ago. The end of the stage is defined exactly at 10,000 Carbon-14 years BP...

, 130,000–18,000 years ago. Otherwise it is covered in quaternary volcanic rock debris.

Climbing route

The ascent of Rishiri is suitable for novice hikers, but can be challenging in places. There is a campsite partway up the mountain from the dock, and an unmanned hut located a short distance below the summit. There is also a small shrine at the summit. On clear days the view extends to Hokkaidō, the adjacent island of Rebun, and as far as Sakhalin

Sakhalin

Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...

 Island in Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

.