La Romana or San Juan?

For beaches the two are evenly matched, but they work in very different ways. La Romana's own waterfront is a working river mouth, so you stay along the calm, pale sand of Bayahibe and Dominicus a short drive east. The best days are spent on boats: snorkelling off Catalina, and the starfish sandbars of Saona, which get crowded at midday.

San Juan has its beaches right in the city. You can walk from a Condado or Isla Verde hotel onto the sand, and El Escambrón is minutes from the old town. The open Atlantic is rougher here, though, with strong currents in places, so it pays to use the lifeguarded balnearios or drive out to Luquillo for calm water.

San Juan is far more rewarding for eating out. Puerto Rican cooking gives you mofongo, alcapurrias and slow-roasted pork. There are kiosks along the Piñones shore, roast-pork stalls up in Guavate, and chef-led restaurants in Santurce and Condado, with mountain-grown coffee to finish.

La Romana's cooking is honest Dominican fare: rice and beans, sancocho, and fried fish with tostones at the Bayahibe grills. Most visitors eat at their all-inclusive, though, and the scene beyond that is thin.

For sightseeing, La Romana has one place and a short list. Altos de Chavón is a handsome stone village built in the late twentieth century as a copy of an old Mediterranean hill town, high above the river gorge, and its small museum of Taíno pottery and ceremonial objects is worth an hour. Add the central park and the Santa Rosa de Lima church in town, and a single morning covers it.

Old San Juan is the genuine article. Its pastel colonial houses on blue-cobbled streets go back nearly five centuries, and the El Morro and San Cristóbal forts, the city walls and La Fortaleza together form a World Heritage site you can walk in a day. The cathedral holds Ponce de León's tomb, and with the island art at the Museo de Arte de Puerto Rico in Santurce, the sights fill a couple of unhurried days.

After dark the gap is wide. San Juan goes out late from Thursday to Saturday, with crowds drinking in the street at La Placita, salsa and reggaeton along Calle San Sebastián, and casinos and clubs in Condado and Isla Verde.

La Romana's nights are local and low-key: beer and bachata outside a colmado, the odd weekend discoteca, and a few marina and beach bars that go quiet by late evening. Most visitors stay in for the hotel show.

San Juan gives you more range. El Yunque's rainforest trails and waterfalls are under an hour away, and near Fajardo you can kayak at night through Laguna Grande's glowing water. There are also mangroves at Piñones and winter surf along the north coast.

La Romana's landscape is flat, dry coastal forest, so its strength is the water. Bayahibe is one of the Dominican Republic's main dive centres, with wrecks, reef walls and an underwater museum of sunken cannons, and Parque Nacional del Este adds mangroves and frigatebirds. On land, though, there is little to hike.

Day trips are equally good from both, and one contrast stands out. La Romana's best outing is to the Ciudad Colonial of Santo Domingo, about an hour and a half away, which supplies the old-city history the town itself lacks. The Taíno rock art at Cueva de las Maravillas and the basilica at Higüey are closer.

From San Juan, the trips add variety rather than history. Ponce has its plaza and art museum, Loíza is the home of bomba, and the rum distillery at Cataño is a short ferry ride away. Culebra and Vieques are better saved for an overnight stay.

Both work well with children, in different styles. La Romana is a resort-based family stay: kids' clubs, pools and shallow, calm water at Dominicus, plus the starfish sandbar at Saona as the big outing. Outside the hotels there is very little for children, and families tend to stay put.

San Juan gives children more to explore, from El Morro's tunnels and cannons and kites on the lawn outside to the short paved trails at El Yunque. English is widely spoken and US standards make daily life easy. The steep cobbles are harder going with a pushchair.

Neither is easy without wheels, but San Juan is the simpler of the two. Its old town is compact enough to walk, and ride-hailing makes the short hops to Condado and Isla Verde straightforward, though you will still want a car or a tour for the island.

La Romana is a string of separate places along a coastal highway. Visitors depend on hotel transfers, taxis and excursion pick-ups, only Bayahibe village can be walked, and the roads are poorly lit after dark.

San Juan gives you more choice: Plaza Las Américas, a short run of designer shops on Ashford Avenue, and carved santos, vejigante masks and guayaberas in the old town.

La Romana's shopping is narrow but distinctive. Hand-rolled cigars from the town's own factories are the thing to buy, along with larimar and amber jewellery at Altos de Chavón.

La Romana is the cheaper of the two. A mid-range all-inclusive in Bayahibe or Dominicus is fairly priced for the Caribbean, and if you live locally in town it costs very little. Boat trips and taxis are where your spending climbs.

San Juan runs at US mainland prices. Beachfront rooms are expensive in winter, and restaurant bills come with tips and taxes added, so the kiosks and roadside stalls are where you save.

San Juan has a real performance life. You can join an open bomba session, dance to a salsa band in Santurce, hear the Puerto Rico Symphony at the Centro de Bellas Artes, or catch the long-running Casals Festival.

La Romana has no season to plan around. The one exception is the occasional big concert at the Altos de Chavón amphitheatre above the river gorge, which makes a striking setting if you happen to be there for one.

Neither city has a spa tradition of its own, and in both places the resort hotels carry the offer. What differs is the setting. La Romana is the calmer place to switch off, with days that slip into a swim-and-siesta rhythm, and Bayahibe goes quiet once the day boats leave.

San Juan has more yoga around its beach districts, but outside the hotels it is a loud city of traffic and music, and for real quiet you have to travel out to the countryside or the small islands.