Puerto Vallarta or San Miguel de Allende?

This is the sharpest contrast between the two. In Puerto Vallarta the whole stay revolves around Banderas Bay. There are loungers on Playa Los Muertos, coves such as Yelapa that you reach by boat and the calm, flat sands of Nuevo Vallarta, with the surf beaches of Sayulita about an hour north.

San Miguel de Allende sits on the high central plateau with no coast in reach. The nearest thing to a swim is a hotel pool or a soak in the spring-fed pools outside town, so anyone who wants sea and sand needs a separate coastal leg.

Both towns eat well for their size, but from different larders. Puerto Vallarta's strength is the Pacific: fish grilled zarandeado on the beach, ceviche, aguachile and marlin tacos, washed down with raicilla.

San Miguel cooks from the highland Bajío, with nopal, mesquite and local cheeses served in colonial courtyards and on rooftops facing the Parroquia. To drink there are wines from Guanajuato's high desert, and gorditas at the market for a cheap lunch. In both, the places on the seafront or the main square are safer and dearer, and the better meals are found a few streets back.

San Miguel de Allende is the town for sightseeing. Its UNESCO-listed centre has ochre façades, carved doorways and the pink spires of the Parroquia. Add the baroque San Felipe Neri, the Casa de Allende and the Siqueiros mural at Bellas Artes, and you have two full days of looking, even without major museums.

Puerto Vallarta is an attractive old fishing town instead. The crown-topped Guadalupe church, the bronze sculptures along the Malecón and the small museums on the Cuale island fill an afternoon.

Puerto Vallarta stays out much later. Open-fronted dance clubs on the Malecón fill after midnight. The Zona Romántica adds rooftop and mezcal bars and one of Latin America's best-established gay scenes, though everything thins out in summer.

In San Miguel an evening means drinks on a rooftop as the Parroquia lights up, then cantinas and mezcal bars near the Jardín. At weekends a few dance bars stay open late, but on weeknights the town goes quiet after dinner and there is no real club scene.

Puerto Vallarta has much the stronger natural setting. Jungle ridges of the Sierra Madre fall straight into the bay, humpback whales calve offshore from December to March, and boats run to Los Arcos and the Marietas Islands for snorkelling. Coastal trails follow the roadless south shore.

San Miguel's surroundings are dry highland scrub and cactus. El Charco del Ingenio, horse riding, dirt-road cycling and dawn balloon flights make good mornings out, but there is no forest or water to build whole days around.

San Miguel de Allende is the better base for excursions. Guanajuato's painted ravine city and Querétaro's aqueduct and convents are each about an hour away. The murals of Atotonilco, Dolores Hidalgo, the Bernal monolith and the wine country are also within a day's reach.

From Puerto Vallarta most outings run along the coast to Sayulita, San Pancho or Yelapa, which you can only reach by boat. The one real change of scene is the climb inland to the old silver town of San Sebastián del Oeste.

Puerto Vallarta is far easier with children. Nuevo Vallarta has calm sands and family resorts with shallow pools and kids' clubs. Whale and snorkelling trips, water parks and turtle releases keep the days full, as long as you avoid the summer heat.

San Miguel is an adult town of galleries and rooftop bars. Older children may enjoy the spring pools, a horse ride or the fiesta fireworks, but younger ones soon run out of things to do. Both towns have steep cobbled streets that make pushchairs hard work.

Neither town is easy underfoot, and the difficulties differ. Only the old centre and Zona Romántica of Puerto Vallarta are walkable, and the town stretches a long way along the bay. Moving between the hotel zone, the marina and Nuevo Vallarta means taxis, ride-hailing or buses signed only on the windscreen, and water taxis serve the south shore.

San Miguel is compact, with everything a visitor wants within a walk of the Jardín, but the stony climbs at about 1,900m are tiring. It has no airport, so you arrive by shuttle from Querétaro or León, and day trips beyond the main bus routes need a driver.

San Miguel de Allende is the better place to shop for crafts and the home. There is the stepped Mercado de Artesanías, design shops selling talavera tiles, carved furniture and folk art, and artists' studios in a former textile mill. The range is wider and the quality higher.

Puerto Vallarta's most distinctive buys are Huichol yarn paintings and beadwork. There are also galleries in the old centre and stalls at the Mercado Municipal by the Cuale, but mass-produced souvenirs take up much of the space. Neither town is a place for fashion.

Puerto Vallarta is the cheaper of the two, though both charge visitor prices in their showcase areas. Beachfront hotels, all-inclusives and boat tours cost far more than the taco stands, local buses and guesthouses in the old centre. Coming outside the winter high season helps.

In San Miguel, the boutique hotels in colonial houses and the restaurants around the Jardín make it one of Mexico's dearer towns, especially at weekends and during festivals. Market lunches, cantinas and the churches and streets, which cost nothing, keep the bill down.

San Miguel has the edge in music and performance. The nineteenth-century Teatro Ángela Peralta hosts concerts and dance, long-established chamber music and jazz festivals fill their seasons, and the Alborada and Holy Week bring traditional dance into the streets.

Puerto Vallarta's stage is more informal: drag, comedy and revues in the Zona Romántica cabarets through the winter, plus bar bands, mariachis and the Papantla flyers on the Malecón. In both towns, serious classical programming is thin.

San Miguel de Allende is the more restful choice. The dry, mild air and slow mornings in courtyards suit doing very little. The hot mineral pools and domed grottoes towards Atotonilco, about fifteen minutes away, offer a kind of thermal bathing that the coast lacks.

Puerto Vallarta's version of relaxing is beach-based: sunsets, resort spas, massage on the sand and yoga retreats in the south-shore villages. Both towns offer the temazcal sweat lodge. The Malecón can be noisy late at night, so for real quiet you need to stay south of the centre.