San Marcos is a city in the North County region of San Diego County, California, with a population of about 94,800 in the 2020 census. Its name is Spanish for 'St. Mark.' The city is bordered by Escondido to the east, Carlsbad to the west, Vista to the northwest, and Encinitas to the southwest, placing it in the heart of inland North County, a short drive from the Pacific coast. Higher education defines much of San Marcos' identity. California State University San Marcos, a campus of the California State University system, and Palomar College, a large community college, both call the city home, bringing students, faculty, and cultural activity. That academic presence, combined with North County's biotech, medical, and technology employers, gives San Marcos a youthful, educated population and a diversified local economy. The city's residential landscape is shaped by master-planned communities. Lake San Marcos, built around an 80-acre man-made lake originally created for irrigation and now used for recreation, is one of the area's best-known neighborhoods. San Elijo Hills, a newer master-planned community with trails and a town center, and the Discovery Lake area, with its lakeside walking paths and open space, add to the mix. Downtown San Marcos offers a walkable commercial core with dining and shopping along its main streets. San Marcos combines inland North County's more spacious and comparatively affordable housing with close access to the beaches of Carlsbad, Encinitas, and Oceanside, plus the broader San Diego region to the south via the Interstate 15 corridor. It appeals to families, students, and professionals seeking a college-town atmosphere, planned neighborhoods, strong schools, and a central North County location.