My husband and I (no kids) are flying into San Diego for work, but we have 3-4 days on our own before our work convention starts in La Jolla. We have been to San Diego recently, and were looking for some ideas of where to go outside of San Diego for 3-4 days (we would fly into San Diego, stay in a hotel in another city for 3-4 days and then drive back to La Jolla for work). We love to hike and do outdoor things. Any ideas/suggestions would be great. Thank you!