San Marcos, California, is a city located in San Diego County. It is known for its beautiful landscapes, including rolling hills and scenic views. The city has a population of around 100,000 residents and offers a mix of suburban and urban living. The area is home to several parks, such as Double Peak Park, which provides hiking trails and picnic areas. San Marcos also hosts California State University San Marcos, contributing to the local economy and educational opportunities. The city is well-connected by major roads, making it accessible to nearby attractions in San Diego.