Getting active in Belém usually means taking a boat ride. For more energetic pursuits, from beach swimming to jungle hiking, you'll need to head up- or downriver.

Surf the Pororoca!

Every month or so, when alignment of the sun and moon makes tides their strongest, powerful waves can form at the mouth of certain rivers and barrel upstream with tremendous force. The phenomenon – which occurs when the tide briefly overpowers the force of the river – is technically a ‘tidal bore’ but in Brazil is better known as the pororoca, an indigenous word for ‘mighty noise.’ And no wonder: the waves can reach heights of 4m and speeds of 30km/h, and can rip full-sized trees off the bank with their force.

All of which is music to the ears of extreme surfers (and wave-surfing kayakers) in search of the mythic ‘endless wave.' The record for the longest ride is 37 minutes, covering nearly 13km. Surfers generally report the pororoca to be stronger than a like-sized ocean wave, and it constantly changes size and speed according to the river’s contours. What’s more, the water is loaded with debris that’s been swept off the shore and river bottom, including tree trunks and abandoned canoes. (At least the caimans tend to stay away.)

The National Pororoca Surfing Championship has been held at the town of São Domingos do Capim, 120km east of Belém on the Rio Guamá, since 1999. (A related competition is held on the Rio Araguari in Amapá.) The event usually takes place in March, on the full moon nearest the spring equinox, when the pororoca is strongest. The bash draws top-ranked surfers and includes street fairs, cultural performances, even a Miss Pororoca competition. A paved road makes getting there easier, though there still is no direct service; from Belém, go to Castanhal and transfer. Alternatively, Amazon Star Turismo, a travel agency in Belém, organizes pororoca packages.

Boat Trips

There are plenty of possibilities for getting out on the river. They include:

Amazon Star Turismo Organizes day trips around Belém, including birdwatching, nature walks and city tours (per person R$150 to R$300), plus overnight tours combining these options, and multiday packages to Ilha de Marajó.

Valeverde Runs a variety of short tours on the river (per person R$50 to R$175), including sunrise trips and pleasant evening cruises. Valeverde has an office and daily schedule at the pier at Estação das Docas; in most cases you can simply show up.