Two multi-day visits to the San Diego area separated by over 20 years hardly make me an expert on the city. On both occasions, I stayed with friends in La Jolla, so I technically spent more time there than in San Diego proper. Nonetheless, in a city not significantly known for must-see cultural attractions, I acquired a reasonable feel for what a visitor may do here.
Cabrillo National Monument ♥♥ offers amazing views, walking paths, just the right amount of historical and local context, interesting room displays in the lighthouse, and a couple of other small expositions. There is also a most agreeable coastal path. Well worth half of the day for a visit.
Coronado Beach ♥ is another popular location to go to. The north side, centered around the ferry, has a great promenade facing downtown San Diego (as well as a pleasant seaside strip mall). You can rent bikes or family surreys for a leisurely ride along the promenade. On the south side, the famous Hotel del Coronado anchors the area full of eye-catching houses. (Note: parking is usually easy by the ferry but can be very challenging by the hotel).
Downtown San Diego itself is not thought of as a destination by the locals, although Gaslamp Historic District may be charming enough.
Old Town San Diego is a nice attraction – with the added bonus of being free – although its small museum exhibits have limited opening hours. There are plenty of attractive artisanal shops and occasional entertainment to compensate for that. Also, a weekend street market closes a couple of streets nearby (neither too big nor fancy).
At the northern edge of San Diego boundaries, Torrey Pines State Preserve ♥♥ is a fantastic nature area, with great views, and nice hikes. Miles of beaches lie below – the majority with no amenities beyond designated parking.
On the campus of US San Diego, Birch Aquarium is a popular attraction. If you have local friends who can guide you, just off the aquarium parking lot, an obscure path leads to a small clearing called Hidden Swings, with a great view over La Jolla coastline.
West Coast is obviously more about catching sunsets, with many popular points, such as Ellen Browning Scripps Memorial Pier in La Jolla. But early risers can also catch amazing sunrises: drive up to Mount Soledad ♥ to the Veterans Memorial at its highest point for a great view of the rising sun.
Driving through and strolling about the coastal towns of Del Mar and Solana Beach to the north of La Jolla can be a pleasant diversion. In the latter, Cedros Avenue Design Center is a collection of eclectic shops that are fun to peruse.
One of the key points of interest in the city, Balboa Park, which is home to several potentially interesting museums as well as the San Diego Zoo, should feature on most itineraries in town. SeaWorld ♥ is another renowned attraction, one of the largest of its kind.
A couple of places worthy of recommendation: Din Tai Fung (in La Jolla center), a super-popular fantastic dim sum place; Madeleine (in Solana Beach), an unbeatable choice for a French-cuisine brunch.