Foz do Iguacu or Puerto Iguazu?

Neither town is anywhere near the sea, but Foz at least offers somewhere to swim. Small towns along the Itaipu reservoir have built sandy lake beaches with lifeguards, half an hour to an hour away by car, and the water is warm all summer.

Puerto Iguazú has nothing similar. The rivers at the edge of town are fast and muddy, and swimming below the falls is not allowed. On both sides of the river, a swim usually means the hotel pool.

Foz has the wider choice. Churrascarias with waiters carrying skewers of beef make the classic night out, weigh-your-plate buffets cover lunch, and one of Brazil's largest Lebanese communities runs family places in the centre serving shawarma and kibbeh.

Puerto Iguazú keeps to simple Argentine cooking: parrillas, milanesas and river fish such as surubí. Its best spot is the Feirinha, where long evening picadas of cheese, cured meat and wine are eaten at market tables. Many people in Foz cross the bridge for exactly this kind of relaxed dinner.

Foz has a few sights beyond the falls, and they are unusual ones. You can take a guided tour across and inside the Itaipu dam, visit the white-domed Omar Ibn Al-Khattab mosque, and see the Chen Tien temple's rows of statues looking out towards Paraguay.

Puerto Iguazú has almost nothing in town apart from the Hito Tres Fronteras obelisk, which looks back at Foz's own marker across the water. Its one distinctive outing is a visit to a Mbyá Guaraní community in the forest. Neither town has an old quarter or a museum worth planning around.

Foz is the better place for a night out, though only in a modest way. Its main evening avenue has a short run of bars and open-air terraces, busiest from Thursday to Saturday with local students, and a few clubs stay open late at weekends.

In Puerto Iguazú, an evening means a late Argentine dinner and then a beer garden full of travellers, and most of them are in bed early so they can reach the park when it opens. The town has a casino on its edge and a couple of small dance spots at weekends. People in Puerto Iguazú who want a livelier night cross the bridge to Foz, while visitors from Foz who want a casino go the other way, or into Paraguay.

On nature the two are level, because they share the same falls and the same rainforest. What differs is which side is on your doorstep. From Foz you reach the Brazilian side, a single cliff-edge walkway that shows the whole panorama in half a day, with the bird park at the entrance.

Puerto Iguazú is the base for the Argentine side, which takes longer to see. There is the forest train, catwalks above and beside the drops, the walkway over the upper river to the Devil's Throat, and the Macuco trail to a quieter waterfall. Most visitors see both sides, wherever they stay.

Each town's best day trip is largely the other town. From Foz, people cross into Argentina for Puerto Iguazú and its side of the falls, or into Paraguay to shop in Ciudad del Este. From Puerto Iguazú, they go the other way for Foz and the Itaipu dam.

The Argentine side has one outing of its own: the amethyst and quartz mines at Wanda, about an hour south. From either town the Jesuit missions are too far for a comfortable day, and every border crossing takes extra time.

Foz is slightly easier with children. The Brazilian walkway is short and gentle and has a lift, the bird park's aviaries are right there, and older children can add the Itaipu tour. The big pool hotels make a good base, though the sights are spread out and there are taxi rides between them.

In Puerto Iguazú, the forest train and the drenching boat rides go down well with children, but the park days are long and on foot. The bold coatis need watching around small hands, and once you leave the falls there is little else for children to do.

Puerto Iguazú is simpler to manage. The bus terminal, restaurants and guesthouses are within a few blocks of each other, a regular bus reaches the park in about half an hour, and inside the park the train and walkways do the rest.

Foz is more spread out. The falls are about 20km out along the airport road and Itaipu is on the other side of town, so a few days usually mean several car journeys. From either town, the far side of the river is easiest by taxi or transfer.

Foz is better for shopping, mainly because it is the doorstep to Ciudad del Este and its huge discount galleries of electronics and perfume. It also has duty-free shops, a large mall and Brazilian gemstones.

Puerto Iguazú sells smaller things: cheeses, salami, wine and yerba mate from the Feirinha, Guaraní carvings and baskets, and amethyst from the nearby mines. It is good for edible souvenirs, but neither town has any fashion or design shopping.

Foz is the cheaper base. Mid-range hotels, buffet lunches, churrascaria dinners and taxis to the falls all cost little. Puerto Iguazú's guesthouses, parrillas and park bus are reasonable, but everyday costs there are moderate rather than low, and they rise and fall with Argentina's exchange rate.

On both sides the falls themselves are where the money goes. Foreign visitors pay higher park fees, seeing both sides means two separate tickets, and boat rides and tours add up fast.

Neither town has much to offer, so in practice they are level. The differences are small. Foz's large restaurants put on dinner shows for tour groups that run from samba to tango and Paraguayan harp, and it has a small municipal theatre. In Puerto Iguazú, the best you are likely to find is chamamé accordion music at a local gathering.

Puerto Iguazú is a little more restful. The town goes quiet once the day trippers have gone, and its lodges sit in the forest itself, with massage rooms and terraces that face the trees.

Foz's large resort hotels on the falls road have spas, pools and gardens that make a good rest day, but the town around them is less calm. Neither side has hot springs or a bathing tradition.