The North Coastal area of San Diego County has a geography that is bounded by the Pacific Ocean then the land gently rises to hills with some occassional salt water estuaries.
Camp Pendelton Marine Corps Base is on the northwestern edge of this region and the city next to that base is Oceanside.
The city just south is Carlsbad, which is home to Legoland amusement park, as well as the Carlsbad flower fields. This area has had the most new construction projects in recent years. If you want to live in this area and want a fairly new home (within 10 years old), then Carlsbad may be a good choice.
At the very bottom of North Coast San Diego is Cardiff and Encinitas. Considered to be the affordable alternative to expensive mansions and beach-front property. Surprisingly home prices here are still above average for the median home prices for San Diego.