There is a vacation rental on a 10 acre private mountaintop in Jamul, that is just 30 minutes east of downtown San Diego. The house is built into the boulders, and has a lagoon pool, hottub and fire ring and offers 360 degree views. Red tail hawks soar at eye level, and we woke up above the clouds. Amazing place. Must be experienced to understand. You can book at www.metaphysicalretreat.com
The town of Julian is an hour east of San Diego in the beautiful Cuyamaca mountains. This little mountain town makes a great day trip and a place to get away for some peace. It's a historic settlement that was founded in the 1870s during the goldrush and most importantly to me, Julian is very well known for great apple pie!
If you are looking to some gambling but don't want to drive all the way to Nevada, then Barona Valley Ranch Resort and Casino is the place to go. One of the leading resort destinations in California, it offers visitors the peace and tranquility of a sprawling mountain escape as well as the best casino action in California (and it's located just 30 minutes outside of San Diego).
Ask someone to lead you to Old Highway 80 just outside of El Cajon. If you stay on that highway, you'll come into Flynn Springs (if you're not careful, you'll miss it!). There's an old general store there that has been there forever and a day. THAT is what I consider to be one of San Diego County's best-kept secrets. That - and Sunset Cliffs near Ocean Beach. There are a LOT of secluded beaches in that area.