Official Site: https://www.nps.gov/elma/index.htm
Wikipedia: https://en.wikipedia.org/wiki/El_Malpais_National_Monument
El Malpais National Monument is a National Monument located in western New Mexico, in the Southwestern United States. The name El Malpais is from the Spanish term Malpaís, meaning badlands, due to the extremely barren and dramatic volcanic field that covers much of the park's area.
The lava flows, cinder cones, and other volcanic features of El Malpais are part of the Zuni-Bandera volcanic field, the second largest volcanic field in the Basin and Range Province. (Wiwkipedia)