Carlsbad, California. Wikipedia description (https://en.wikipedia.org/wiki/Cerro_de_la_Calavera):
Cerro de la Calavera (also known as Mount Calavera) is an 513 ft (156 m)[1] ancient plug dome volcano that last erupted 22 million years ago during the subduction of the Farallon Plate.[3][better source needed] It is located within the city of Carlsbad, California in the United States.
The caldera:
a little wild 
Carlsbad, CA is where Aptera http://aptera.us/ is headquartered.
Paul L.
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