San Antonio or San Diego?

San Antonio has no coast to speak of. The Gulf is too far for a day at the sea to fit easily, so water time means floating the clear Comal or San Marcos rivers on an inner tube, swimming in Hill Country holes under limestone bluffs, or using a hotel pool.

San Diego is built around its shoreline. There is the wide sand at Coronado, the boardwalk scene of Mission and Pacific Beach, gentle surf at La Jolla Shores and calm water for toddlers in Mission Bay. The Pacific stays cool, though, and is only really pleasant in late summer.

Both cities eat best at the cheap end and both lean on Mexico, but they lean on different parts of it. San Antonio is the home of Tex-Mex, with breakfast tacos, enchiladas in chili gravy and Sunday barbacoa, plus Central Texas brisket and pan dulce from neighbourhood panaderías.

San Diego looks to Baja instead, with fish tacos, carne asada and the fries-stuffed California burrito, and it adds a large craft beer scene and the Asian kitchens of Convoy Street. Go to San Antonio to eat deeply within one tradition, and to San Diego for more range and a taproom afterwards.

San Antonio has the stronger history. The Alamo stands downtown, and the missions of San José, Concepción, San Juan and Espada follow the river south as a UNESCO World Heritage Site. The German mansions of King William and the Latin American collections at the San Antonio Museum of Art add depth.

San Diego's culture is concentrated in Balboa Park, where a day takes in most of its museums. The USS Midway, Old Town's adobes and the state's first mission fill out the rest, but they are pleasant visits rather than the main reason to come.

Neither city keeps late hours, but San Diego gives more choice. The Gaslamp Quarter has rooftop bars and dance clubs, Pacific Beach has a rowdy strip full of students and surfers, and Hillcrest is the centre of a sizeable gay scene.

Evenings in San Antonio are easier and earlier. You might have a margarita by the River Walk, a cold beer at an open-sided icehouse in Southtown or on the St. Mary's Strip, or dance at a Tejano dance hall, which San Diego has nothing like.

San Diego is the far stronger outdoor destination. On the coast there are the sandstone bluffs at Torrey Pines, sea lions at La Jolla Cove, tide pools at Cabrillo and grey whales passing in winter. Within an hour or two inland you reach pine forest in the Laguna Mountains and the Anza-Borrego desert.

San Antonio's landscape is gentler: live oaks, cypress rivers, show caves north of the city and bluebonnets in spring, with the granite dome of Enchanted Rock as the longest outing. Long, very hot summers keep hiking to the cooler half of the year.

A day out from San Antonio means a drive into the Hill Country. You can walk the long main street of German-founded Fredericksburg and visit the wineries east of town, see the old dance hall at Gruene and cowboy Bandera, and stop at the LBJ Ranch on the way. Austin's Capitol and music are also within reach.

From San Diego the outings run south over the border and north along the coast. Tijuana is a trolley ride and a short walk away, the Valle de Guadalupe vineyards lie further into Baja, and trains reach Carlsbad and Encinitas without a car. Temecula's wine country and the apple-pie town of Julian need the car again.

San Diego is one of the best family cities anywhere. Its world-class zoo, the open-plains Safari Park, Legoland for younger children and SeaWorld on Mission Bay would fill a week, and the mild weather and beaches fill the gaps.

San Antonio is also easy with children, with its own SeaWorld, the roller coasters of Six Flags Fiesta Texas, the DoSeum and dinosaurs at the Witte. However, the July and August heat shapes every day there in a way it never does on the Californian coast.

Once you leave the centre you will want a car in either city, so the difference is what you can do without one. San Antonio has no metro or light rail, but the shaded River Walk links its downtown sights on foot, and a riverside cycle path leads out to the missions.

San Diego has a trolley from downtown to Old Town and the border, and coastal trains to the beach towns, so a few outings work without driving. La Jolla, Legoland and the Safari Park still need a car, and beach parking is tight on summer weekends.

Neither city is worth a trip for shopping, and both come down mostly to malls and outlets. San Antonio has the more distinctive local buys: Mexican crafts and piñatas at El Mercado in Market Square, and Western boots and hats. San Diego is better for luxury brands at Fashion Valley, vintage shops in North Park and surfwear in the beach towns.

In San Antonio the fixed costs are modest, and most of the bigger spending is your choice. The extras are a hire car for anything beyond downtown, theme park tickets if you bring children, and the higher prices you pay for a room or table with a river view. If you stay a street back from the water and skip the parks, the trip stays reasonable.

San Diego is expensive even before you add extras. The room is the largest outlay, above all near the sand in summer, and a car brings parking charges on top. You save most on the coast, because beaches, sunsets and Balboa Park's gardens are free, and a taco shop lunch keeps the day's spending down.

San Diego has the stronger theatre. The Old Globe's open-air Shakespeare stage in Balboa Park and the La Jolla Playhouse are serious producing companies that have sent shows to Broadway, and the symphony plays outdoors on the bay in summer.

San Antonio's formal stage is smaller, with the Tobin Center and the ornate Majestic. Its real character is Tejano and conjunto accordion music, heard in dance halls, at Fiesta each spring and in mariachi around Market Square.

San Diego is the easier place to unwind. There are resort spas in La Jolla, Coronado and Carlsbad, a long-standing yoga culture in Encinitas, and mild evenings for sunset walks on the sand. In San Antonio, rest means booking a Hill Country resort spa or spending a quiet morning at the Japanese Tea Garden, and the summer heat makes lazy outdoor days tiring.