Carlsbad is a coastal city in the North County region of San Diego County, California, United States. It is a popular tourist destination. Among the nation's top 20 wealthiest large cities, Carlsbad is the 5th richest city in the state of California.Carlsbad's history began with the Luiseño people, as well as some Kumeyaay in the La Costa area. Nearly every reliable freshwater creek had at least one native village, including one called Palamai. The site is located just south of today's Buena Vista Lagoon.