Lençóis Maranhenses trip: dunes, rain lagoons and the way from Rio

At a glance

The park was created by decree on 2 June 1981. UNESCO describes a dune field of about 90,000 ha, the largest in South America, with dunes up to 30 m high that move inland by about 4 to 25 m a year. The lagoons between them are fed only by rainwater, with no river flowing in or out, so their shape and place change from season to season.

When the lagoons are full

Maranhão’s tourism secretariat puts the rainy season at roughly January to July, the months when the lagoons form and fill. How much water there is depends on each year’s rain, and later in the year many temporary lagoons shrink. A few hold water much longer: the state secretariat says Lagoa da Gaivota near Santo Amaro, the park’s largest, never dries, and Embratur names Lagoa da Esperança and Peixe as lagoons that last through the dry season.

The park is open all year (ICMBio). If you travel later in the year, we ask local operators about the water level for your dates before you book.

Barreirinhas, Santo Amaro or Atins

Lagoon circuits

ICMBio calls the outings circuits. You buy them from an agency in town, shared or private, and ride in an authorized vehicle. ICMBio advises asking providers to show their badge and authorization.

From Barreirinhas

• Lagoa Azul: a half-day 4x4 trip with a swimming stop, usually in the morning.
• Lagoa Bonita: 4x4 over sand roads, then a wooden staircase up the dunes; the circuit also takes in Clone and Descanso lagoons.
• Lagoa da Esperança: more than an hour from Barreirinhas, on the border with Santo Amaro.

From Santo Amaro

• Andorinha: closest to town, by vehicle or on foot, with the Andorinha, Maçarico and Gaivota lagoons.
• Emendadas: two lagoons that join at high water, reached by a long walk over dunes, usually in the afternoon for sunset.
• Betânia: the shallow Rio Alegre and the Betânia, Pedra and Cajueirinho lagoons.
• América: by boat only, along the Rio Alegre.
• Rancharia: a full day, with lunch at a support base in the park.

From Atins

A route runs along the park beach to the mouth of the Rio Negro and Lagoa Verde. ICMBio advises asking providers first whether it is passable, since it depends on water in the river.

The dune trek

The Travessia dos Lençóis crosses from the Atins side to Santo Amaro. Embratur describes a three-day version of about 32 km in stages of about 6, 12 and 14 km, with nights in the villages of Baixa Grande and Queimada dos Britos. ICMBio’s rules for the 2026 season:

• book stays in the communities before starting and carry the confirmation;
• no more than 10 people per guide;
• fill in an entry form before and an exit form after the trek;
• each group carries a human waste container;
• glass and campfires are not allowed anywhere in the park.

ICMBio recommends at least three litres of water per person per day on the trek, since support points are few. Embratur adds that ATMs do not work in the region, so carry cash.

Park rules

Only vehicles, drivers and guides authorized by ICMBio may carry visitors, and they hold a badge and a valid authorization. Maranhão’s tourism secretariat also advises going with local guides: the park has no signs and it is easy to get lost in the dunes.

• Private cars, motorbikes, buggies, quad bikes and UTVs are not allowed, and nobody may drive over the open dune field.
• Selling, carrying and drinking alcohol is prohibited.
• Campfires, barbecues, camping stoves and pets are prohibited.

Getting there from Rio

1. Fly from Rio to São Luís. Direct services change with the schedule, so check routes for your dates. Our airports guide covers leaving Rio.
2. From São Luís to Barreirinhas it is about 3 hours by car, and daily buses leave from the São Luís bus terminal (state tourism secretariat).
3. For Santo Amaro, the road goes via BR-135, BR-402 and MA-320 (ICMBio).
4. Atins is reached from Barreirinhas by 4x4 or boat.

How many days

The journey from Rio takes most of a day each way. Lagoa Azul and Lagoa Bonita fit into half-day outings; Santo Amaro, Atins or the trek add days. We usually plan 3 to 5 days on the ground. To fit the park into a longer route, see our two-week Brazil itinerary.

What to bring and health

• ICMBio lists water, repellent and sunscreen; the state tourism secretariat adds swimwear and light clothes; Embratur adds a hat and sunglasses.
• Leave glass bottles at the hotel.
• CDC recommends yellow fever vaccination for travelers aged 9 months and older going to Maranhão, and reports malaria in the state, rare in São Luís. Your doctor decides on prevention; see Brazil health tips.

The US State Department rates Brazil at Level 2 (advisory of 31 August 2026). Emergency numbers: 190 police, 192 ambulance, 193 fire brigade. Check entry requirements on official websites.

What to tell us in your request

• Travel dates and days available for Lençóis
• How many travelers, ages of children
• Base: Barreirinhas, Santo Amaro, Atins, or a mix
• Interest in the dune trek, kitesurf or easy lagoon outings
• Guide language
• Flights, if already booked

How we help

We join Rio and Lençóis into one route: transfers from São Luís airport to Barreirinhas, Santo Amaro or Atins, lagoon circuits with authorized 4x4 operators, a guide who speaks your language and places to stay. We check the lagoon water for your dates and stay your single contact during the trip. We do not sell flights, but we plan around yours. Terms and payment are set out in the proposal, and you pay nothing before you confirm. See our private trips and how we work.