La Fortuna or Tamarindo?

This is the widest gap between the two. La Fortuna has no beach at all. Swimming there means the churning pool below the waterfall, a calm bend of river or a corner of Lake Arenal, which are pleasant on a hot afternoon but nothing more.

Tamarindo is built around its bay, which has warm water and soft, steady waves for learning to surf. Other beaches are close by: quieter Langosta, wild Playa Grande, Avellanas for stronger surfers and the clearer water of Conchal for snorkelling. Watch for rip currents, and keep clear of the river mouth, where crocodiles live.

Tamarindo has the wider choice of the two, though eating is modest in both towns. La Fortuna keeps it simple, with casados and gallo pinto at family-run sodas and steakhouses and pizza aimed at tour groups. Its one distinctive offer is out on the farms, where you taste chocolate made from the bean and coffee grown on Arenal's volcanic soil.

In Tamarindo, foreign residents have widened the menu with fish taco stands, poke bowls, wood-fired pizza, Argentine grills and a few more ambitious dinner places. The sodas add ceviche made with the day's catch, though after a week the choices start to repeat.

Neither has much to see. One began as a farming settlement and the other as a fishing village, and both grew into bases for visitors, so neither has museums or old streets. The difference is in the heritage nearby. From La Fortuna that means the Maleku indigenous communities to the north, and from Tamarindo the older inland towns of the Nicoya Peninsula. La Fortuna does at least have a white church with Arenal rising behind it for photographs.

Tamarindo is the place for a night out. Sunset drinks on the sand lead on to open-air bars along the main road and, on busy nights, to dance clubs playing reggaeton and electronic music. A different venue takes the big night each week. It is a small scene, though, and the same crowd moves around a few blocks.

In La Fortuna most evenings are spent in a hot spring or at dinner. There are a handful of bars and the odd salsa night at the weekend, but the town is quiet by late evening because most visitors are up at dawn for a tour.

Both are strong for the outdoors, but La Fortuna is the more complete base. Arenal's cone, the lava-flow trails, primary rainforest, the 70m waterfall and canopy bridges with sloths and toucans are all close by. You can go rafting on the Balsa and Toro rivers, canyoning, or kitesurfing on Lake Arenal, and Río Celeste and Caño Negro are further out.

Tamarindo's outdoors is mostly the sea: surfing, diving at the Catalinas Islands, kayaking in the mangroves and leatherback turtles nesting on Playa Grande. Its dry forest turns brown from December to April, and the nearest volcano park, Rincon de la Vieja, is about two hours inland.

For outings to other towns, Tamarindo has the edge, though the list is short from both. La Fortuna's excursions are mostly into the landscape, and the places to visit come down to Zarcero, with its clipped topiary garden in front of the church, and the Maleku villages near Guatuso. Monteverde is about three hours away by jeep and boat across the lake, so it works better as a transfer than as a day out.

Tamarindo has a little more. In Guaitil, about 45 minutes inland, families make Chorotega-style pottery and fire it in traditional kilns. Nicoya has one of the country's oldest colonial churches, Santa Cruz is the region's folkloric centre, and Nosara or Playas del Coco make a change of beach, although the roads are slow in the wet season.

For outdoor families the two are about equal. Both offer zip lines, horse rides and wildlife, and neither has zoos or museums for children, so the difference is in what fills the days. La Fortuna has hot-spring pools with water slides and sloths to spot from the hanging bridges. The steep stairs to the waterfall are hard with small children, though, and frequent rain means more time in the car.

In Tamarindo the days revolve around the sea, with children's surf lessons, calm low-tide water at Langosta and turtle-nesting walks at night. Parents need to watch for rip currents and the estuary, and families usually stay away from the noisy main strip.

Both centres are easy to walk and hard work beyond, but Tamarindo is a little easier. Its beach doubles as a footpath, golf carts and bicycles cover the short hop to Langosta, and Liberia's airport is about an hour away.

In La Fortuna the hot springs, trails and bridges are strung out over several kilometres along the road to the lake, and local buses are sparse. You need a car, a taxi or tour transport for almost everything. In Tamarindo a four-wheel drive helps on the unpaved roads to the southern beaches, and in both places the roads are slow in the rain.

Tamarindo sells surf gear and beachwear, and La Fortuna sells coffee and crafts. In La Fortuna, the souvenir shops around the central park have hammocks, painted masks, carved bowls and Maleku crafts, plus bags of local coffee and chocolate that make good gifts to eat.

Tamarindo has a little more to browse. Along the main road there are surf shops for boards and rash guards, boutiques selling swimwear and linen, and stalls with Guaitil pottery, although it is more rewarding to buy the pottery in the village itself.

The two cost much the same, and neither is cheap. In La Fortuna the bill grows with the activities, from hot-spring resorts to rafting and canyoning. Budget travellers can save with the free river springs and by walking the trails on their own.

In Tamarindo the rooms, meals and drinks themselves cost close to North American levels, and transport adds more because little is within walking distance. The beach is free, though, and prices drop in the wet season.

Neither has theatres or concert halls, so this hardly affects the choice. What there is differs a little. Tamarindo has acoustic sets and local bands in beach bars and fire dancers on the sand, and Guanacaste folk music turns up at festivals in nearby Santa Cruz. In La Fortuna you might find a bar band at the weekend or folkloric dance with dinner.

La Fortuna is the clear choice for unwinding. Thermal water from beneath Arenal fills terraced pools and cascades in rainforest gardens, at both large complexes and quieter, more natural ones, and there is also a free stretch of warm river. Spa treatments and open-air yoga round it out.

Tamarindo relaxes in a different way, with yoga studios, retreats that combine surfing and yoga, and massages on the beach. It has no bathing tradition. A calm stay depends on sleeping at Langosta or Playa Grande, away from the traffic and late bars of the main strip.