Tolbachik is a volcanic complex

Complex volcano

A complex volcano, also called a compound volcano, is a volcano with more than one feature. They form because changes of their eruptive characteristics or the location of multiple vents in an area...

 on the Kamchatka Peninsula

Kamchatka Peninsula

The Kamchatka Peninsula is a peninsula in the Russian Far East, with an area of . It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west...

 in the far east of 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...

. It consists of two volcanoes, Plosky (flat) Tolbachik (3,085 m) and Ostry (sharp) Tolbachik (3,682 m), which as the names suggest are respectively a flat-topped shield volcano

Shield volcano

A shield volcano is a type of volcano usually built almost entirely of fluid lava flows. They are named for their large size and low profile, resembling a warrior's shield. This is caused by the highly fluid lava they erupt, which travels farther than lava erupted from more explosive volcanoes...

 and a peaked 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...

. As Ostry is the mountain's highest point, the entire mountain is often referred to as "Ostry Tolbachik", not to be confused with Ostry

Ostry

Ostry is a stratovolcano located in the northern part of Kamchatka Peninsula, Russia. It comprises higher Ostry volcano and smaller Kutina volcano. Ostry is one of the highest peaks of Sredinny Range.- References :*...

 a separate volcano to the north also on the Kamchatka Peninsula.

Its eruptive history stretches back thousands of years, but the most notable eruption occurred in 1975, commonly known as "The Great Tolbachik Fissure Eruption".