Islay Hill is a

volcanic cone Volcanic cones are among the simplest volcanic landforms. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and s ...

, and is the southernmost of the nine volcanic

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...

s and

hill A hill is a landform that extends above the surrounding terrain. It often has a distinct summit, and is usually applied to peaks which are above elevation compared to the relative landmass, though not as prominent as Mountain, mountains. Hills ...

s that make up the

Nine Sisters The Nine Sisters or the Morros are a chain of twenty-three, although typically only nine are included, volcanic mountains and hills in western San Luis Obispo County, Southern California. They run between Morro Bay and San Luis Obispo. Geograph ...

, located in the

San Luis Obispo County San Luis Obispo County (), officially the County of San Luis Obispo, is a county on the Central Coast of California. As of the 2020 United States census, the population was 282,424. The county seat is San Luis Obispo. Junípero Serra fou ...

of central

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. This chain of extinct, but possibly dormant volcanoes, the eight others

volcanic plug A volcanic plug, also called a volcanic neck or lava neck, is a volcano, volcanic object created when magma hardens within a Volcanic vent, vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if risi ...

s, stretches from

Morro Bay Morro Bay (''Morro'', Spanish for "Hill") is a seaside city in San Luis Obispo County, California, United States. Located on the Central Coast of California, the city's population was 10,757 as of the 2020 census, up from 10,234 at the 2010 ...

southeast to Islay Hill, which is on the southeast side of

San Luis Obispo ; ; ; Chumashan languages, Chumash: ''tiłhini'') is a city and county seat of San Luis Obispo County, California, United States. Located on the Central Coast (California), Central Coast of California, San Luis Obispo is roughly halfway betwee ...

(city).

References

External links

* Nine Sisters Landforms of San Luis Obispo County, California San Luis Obispo, California Volcanic plugs of California Hills of California Volcanoes of California {{SanLuisObispoCountyCA-geo-stub