Puerto Natales or San Pedro de Atacama?

Neither city is a place for a beach trip. Puerto Natales faces a cold, windy fjord with a gravel and rock shore, so the water is for looking at, not for swimming.

San Pedro de Atacama is far inland, but it does offer one unusual swim: floating on the dense salt water at Laguna Cejar or the Baltinache pools. It is a novelty that lasts an hour, not a lazy afternoon. In both places, a hotel or lodge pool is the only real option for a proper swim.

The two are broadly level, with short menus aimed at trekkers and tour groups, but the cooking differs. Puerto Natales serves the cold south: lamb slow-roasted over an open fire, king crab from the channels, hearty stews and local craft beer, with a few kitchens more ambitious than the town's size suggests.

San Pedro de Atacama cooks from the Andes, with quinoa, llama, goat cheese and rica-rica, which even turns up in pisco sours. Along Caracoles, though, the menus start to repeat after a few nights. Neither city has street food or a market to explore.

San Pedro de Atacama has more to see, though nobody comes to either town for its sights. Its whitewashed adobe church has a cactus-wood ceiling, and you can cycle to the Pukará de Quitor fortress above the river and the round dwellings of Tulor, more than two thousand years old.

Puerto Natales has brightly painted timber and corrugated-iron houses, a small museum on the Aónikenk, Kawésqar and sheep-farming history, and the old Bories cold-storage plant. That fills an afternoon, whereas San Pedro's heritage makes a good half-day by bike.

Both towns are quiet well before midnight. In Puerto Natales, the evening means a pub with local craft beer while trekkers trade trail stories in summer.

In San Pedro de Atacama you get pisco sours around outdoor fire pits on Caracoles, then an early night before the geyser tour. Its real night out is an astronomy tour under some of the clearest skies anywhere.

Both are gateways to world-class landscapes, but they could hardly be more different. Puerto Natales leads into Torres del Paine, with the granite towers and the Cuernos, turquoise lakes, glaciers off the Southern Ice Field and pumas on the steppe. You can trek, kayak among icebergs or take a boat up the fjords, as long as you can handle wind and weather that changes by the hour.

San Pedro de Atacama is high desert: the Valle de la Luna dunes, flamingos on the Salar, El Tatio steaming at sunrise and blue lagoons beneath volcanoes. It is reliably sunny all year, but altitude is the constant limit, while Puerto Natales has a season that runs only from spring to autumn.

San Pedro de Atacama has a few more places of human interest within reach. These include the white-stone oasis village of Toconao, Andean hamlets along the tour routes, the old church at Chiu Chiu and the vast copper mine at Chuquicamata.

From Puerto Natales, the Bories plant and the Milodón Cave are about all there is close by. Punta Arenas and El Calafate are too far for a day trip, so they work better as overnight stays.

Puerto Natales is the slightly easier choice with children. It is a small, safe town at sea level, with the life-size sloth at the Milodón Cave and guanacos, rheas and flamingos to spot along the road. Long drives and fierce wind still make it better for older children than toddlers.

San Pedro de Atacama can thrill teenagers with sandboarding, salt-lagoon floating and telescopes. However, the pre-dawn starts, the cold at over 4,000m and the risk of altitude sickness make it hard work for younger ones.

Puerto Natales is easier to get around. Its flat grid is quick to walk, and in season coaches run from the town terminals to the park entrances, with a catamaran and shuttles linking trailheads inside. Out of season the buses thin out.

San Pedro de Atacama has no public transport to its lagoons, geysers or valleys. You either book a minibus tour from Caracoles or hire a car, ideally a high-clearance one. Bikes cover the nearby valleys and ruins, though the heat and sand make it harder than it looks.

In Puerto Natales, shopping serves the trail. There are outdoor clothing and gear shops for whatever you forgot to pack, and supermarkets for stocking up before a multi-day trek. A few craft shops add sheep's wool knitwear, sheepskin and lapis lazuli jewellery.

San Pedro de Atacama leans more towards souvenirs. It has a craft market by the plaza and shops along Caracoles selling alpaca and llama wool jumpers, woven Andean textiles and carvings in volcanic stone. Much of it is the same across the region, but a warm alpaca layer is worth having on the freezing dawn tours. In both towns, an hour covers all the browsing there is.

Both cost more than most of Chile, because supplies have to come a long way. In Puerto Natales, the strain comes from scarce summer rooms and the costs of Torres del Paine: park entry, transfers, glacier boats and refugios.

San Pedro de Atacama is a little easier on the budget, but because almost every sight needs a tour or a car, excursions take a large share of the spending. Set lunches and cycling to the nearby valleys help, just as self-catering and booking early do in the south.

Neither town has a theatre or a regular programme. Puerto Natales gets an occasional guitarist or folk band in a bar.

San Pedro de Atacama brings in panpipe and charango players on busy evenings. During the feast of San Pedro and San Pablo and during Carnival, costumed dance troupes fill its streets.

San Pedro de Atacama is much better for unwinding. It has the Termas de Puritama hot pools stepping down a reed-filled canyon, lodge spas with volcano views, yoga in the village and siestas behind adobe walls. Just leave some empty days between the early tours, because the altitude tires you.

In Puerto Natales, wellness means a sauna or hot tub at a lodge after a day on the trail, and a quiet evening watching the light over the fjord. People go there to exert themselves, not to rest.