There's a lot to see in and around San Diego. Here's a short list of places you might want to explore:
• Anza-Borrego Dessert: Most of eastern San Diego County, which otherwise consists largely of sleepy suburban communities, is taken up by the more than 600,000-acre Anza-Borrego Desert, much of it a state park (free; $5 per vehicle). Some of it can be covered by car, although four-wheel-drive vehicles are necessary for the more obscure - and most interesting - routes. The best time to come is winter, when daytime temperatures stay around the mid-eighties. In the fiercely hot summer, it's best left to the lizards; but when the desert blooms, between March and May, scarlet ocotillo, orange poppies, white lilies, purple verbena and other wild flowers paint a memorable, and fragrant, picture.
• Balboa Park and The San Diego Zoo: Sumptuous Balboa Park contains one of the largest groups of museums in the US, scattered either side and to the south of El Prado, the road that bisects the park. Yet its greatest charms are its trees, gardens, statues, traffic-free promenades and Spanish Colonial-style buildings. The enormous San Diego Zoo (daily: mid June-early Sept 7am-10pm; early Sept-mid June 9am-dusk; last entry an hour before closing; ), immediately north of the main museums, is one of the world's best. Its wide selection of animals, many of them rare, are restrained in "psychological cages," without bars.
• Downtown San Diego and Coronado Island: Always vibrant and active, downtown San Diego is the best place to start exploring. Since the late 1970s, several blocks of 1920s architecture have been stylishly renovated, with the sleek modern bank buildings symbolizing the city's growing economic importance on the Pacific Rim. Downtown is safe by day, but can be unwelcoming at night, as much of it shuts down after business hours. Across San Diego Bay from downtown, the isthmus of Coronado is a well-scrubbed resort community with a major naval station occupying its western end. It's of somewhat limited interest, except for the majestically modern Coronado Bay Bridge, a curving 11,000-foot span that's one of the area's signature images ($1 toll for southbound travelers without passengers), and the historic Hotel del Coronado, around which the town grew.
• Old Town and Presidio Hill: Old Town San Diego, reachable from downtown via the Trolley, is now a state historical park holding a number of original adobe dwellings, plus the inevitable souvenir shops. The stores and restaurants stay open until 10 p.m. or later, but the best time to be around is during the afternoon when you can visit the more interesting of the adobes on the daily free walking tour (2pm). In 1769 Spanish settlers chose Presidio Hill as the site of the first of California's missions. They soon began to build homes at the foot of the hill, which was dominated in turn by Mexican officials and then by early arrivals from the eastern United States.
• Tijuana, Mexico: You could hardly find a more intriguing day-trip out from San Diego than Tijuana, just over the border in Mexico. While far from the most culturally rich place in Mexico, every year twenty million people cross here from the U.S. Most of them are Californians and tourists on day-long shopping expeditions, seeking somewhere cheap and colorful to spend money. Keep in mind, though, that while most items are lower-priced in Tijuana than in the U.S., the quality and safety of the merchandise are sometimes questionable.