This great place to stay , it is in heart of city. I like San Marcos as San Marcos is located in San Diego County, and has a population of about 84,000. The city’s population has exploded over recent years, as the population in the 2000 census was 54,977. San Marcos is most well known as the home of California State University, San Marcos. Popular attractions in the city include the Double Peak Park, the St. Mark Golf Club, Rip Current Brewing, and the Dos Desperados Brewery.