Cerro Cabrillo, also known locally as Cabrillo Peak, is a rocky butte

Butte

A butte is a conspicuous isolated hill with steep, often vertical sides and a small, relatively flat top; it is smaller than mesas, plateaus, and table landform tables. In some regions, such as the north central and northwestern United States, the word is used for any hill...

 in Morro Bay State Park

Morro Bay State Park

Morro Bay State Park is a state park in Morro Bay, in western San Luis Obispo County, California. On the bay’s northeastern edge, there is a saltwater marsh that supports a thriving bird population. -Recreation:...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. The rock outcrop, composed mostly of rhyodacite

Rhyodacite

Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of granodiorite. Phenocrysts of sodium rich plagioclase, sanidine, quartz, and biotite or hornblende are typically set in an aphanitic to glassy light to intermediate...

, is a volcanic plug

Volcanic plug

A volcanic plug, also called a volcanic neck or lava neck, is a volcanic landform created when magma hardens within a vent on an active volcano. When forming, a plug can cause an extreme build-up of pressure if volatile-charged magma is trapped beneath it, and this can sometimes lead to an...

 formed when magma

Magma

Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...

 welled up underneath a layer of softer rock and solidified. The softer overlying rock has since eroded away leaving the distinct rugged shape.
It is one, in a group of nine volcanic plugs in the area known as the Nine Sisters

Nine Sisters

The Nine Sisters or the Morros are a chain of nine volcanic peaks and hills between Morro Bay and San Luis Obispo, California. They are popular with photographers and rock climbers. Their volcanic origin makes them of significant geological interest. They support a wide variety of plant, animal,...

, which includes Morro Rock

Morro Rock

Morro Rock is a volcanic plug located just offshore from Morro Bay, California, at the entrance to Morro Bay Harbor. A causeway connects it with the shore, effectively making it a tied island. The area surrounding the base of Morro Rock can be visited. The rock is protected as the Morro Rock State...

 and Bishop Peak. It is named after Juan Rodríguez Cabrillo

Juan Rodríguez Cabrillo

Juan Rodriguez Cabrillo was a Portuguese explorer noted for his exploration of the west coast of North America on behalf of Spain. Cabrillo was the first European explorer to navigate the coast of present day California in the United States...

, an explorer, who was in the area around 1542.

The peak is popular with hikers and climbers. Its slopes support many wild flowers such as Gentian

Gentian

Gentiana is a genus of flowering plants belonging to the Gentian family , tribe Gentianeae and monophyletic subtribe Gentianinae. With about 400 species, it is considered a large genus.-Habitat:...

, Deer Weed, Soap Plant

Soap plant

The Soap Plants, Soaproots or Amoles are the genus Chlorogalum of flowering plants. Less common names for them include Soap Lilies. They are endemic to western North America, from Oregon to Baja California, and are mostly found in California.The Soap Plants grow as perennial plants, from a bulb,...

, and Mallow

Sidalcea

Sidalcea is a genus of the botanical family Malvaceae. It contains several species of flower known generally as checkerblooms or checkermallows.Selected species:*Sidalcea calycosa - annual checkerbloom...

. On its east side is a rock formation called a tiki

Tiki

Tiki refers to large wood and stone carvings of humanoid forms in Central Eastern Polynesian cultures of the Pacific Ocean. The term is also used in Māori mythology where Tiki is the first man, created by either Tūmatauenga or Tāne. He found the first woman, Marikoriko, in a pond – she seduced him...

because of its resemblance to a Polynesian carving.