Lagoa das Andorinhas: Santo Amaro's Clear-Water Lagoon

Lagoa das Andorinhas sits about 10 minutes by 4x4 from the center of Santo Amaro do Maranhão, making it one of the most accessible lagoons in the Lençóis Maranhenses. The lagoon stretches roughly 1 kilometer and holds water year-round — even in November, when smaller pools have evaporated — so you can swim in it long after the peak season ends.

That reliability matters. Santo Amaro receives a fraction of the visitors that Barreirinhas does, and Andorinhas absorbs them without feeling crowded. On a Tuesday afternoon in July, I counted fewer than 20 people along the entire shoreline. The water shifts between green and blue depending on the light, and the white sand banks are firm enough to walk on barefoot without sinking.

Getting There and Setting Up Your Visit

Santo Amaro do Maranhão lies about 250 kilometers from São Luís. Until recently, the final stretch was a sand road that required a 4x4, but the access has been improved, and regular vans now make the trip from the capital in roughly four hours. From the town center, every lagoon tour begins with a short 4x4 ride over the dunes.

The Circuito Andorinhas

The standard visit is sold as the Circuito Andorinhas, a half-day trip that combines Lagoa das Andorinhas with Lagoa da Gaivota and usually one or two smaller lagoons. Morning departures leave at 9:00 and return around noon; afternoon departures leave at 15:00 and return near 18:00, finishing with sunset over the dunes. Each lagoon stop lasts about 40 minutes — enough for a swim, a walk up the nearest dune, and a few dozen photos.

Prices vary by operator. Shared 4x4 tours cost around R$200 per person, while a private vehicle for up to four people runs about R$1,000. The national park entrance fee is R$10 per person for a three-day bracelet, sold at the park office before departure. (Fees are subject to change — check the official site for current rates.)

Walking In

If you prefer to skip the vehicle, a marked trail leads from the park entrance to Andorinhas in about two hours on foot. The route passes roughly seven smaller lagoons, and the walking is easy — flat stretches interrupted by moderate dune climbs. I would only recommend this between June and September, when the heat is manageable and the trail is obvious. Outside that window, the sand gets loose and the route less defined.

What to Bring

There is no shade at the lagoon and no facilities beyond a basic parking area. Bring water, sunscreen, a hat, and a dry bag for your phone. The 4x4 drivers wait at the lagoon edge, so you can leave larger bags in the vehicle. Cash is useful for the park bracelet and for the occasional snack vendor at the entrance.

What Makes Andorinhas Different

Most lagoons in the Lençóis Maranhenses are shallow — knee-deep by August. Andorinhas is not. It is one of the deepest lagoons in the park, and local guides say it never fully dries out. That depth gives the water a richer color than the pale pools nearby, and it means you can actually swim rather than wade.

Swimming and Kayaking

The lagoon is calm and free of currents. The bottom is soft white sand, and the water is clear enough to see your feet at two meters. Several operators now offer kayak rentals on the lagoon — paddling across the 1-kilometer length takes about 25 minutes at an easy pace and gives you a view of the dune field that you cannot get from the shore.

The far end of the lagoon is usually empty. Most groups cluster near the 4x4 parking area, so a 10-minute walk along the sand bank puts you in near-total quiet. That is where I would spend the afternoon.

The Surrounding Dunes

A short climb up the dune behind the lagoon rewards you with a full view of the water — you can see almost the entire 1-kilometer length from the ridge. The climb takes five minutes and is steep enough to make you breathe hard, but the sand is cool underfoot in the morning. Photographers should aim for the afternoon circuit: the light turns golden around 17:00, and the lagoon reflects the sky like a mirror.

When to Go

The lagoons fill during the rainy season, which runs from January to May. By June, the water is at its highest and the skies are clear. July and August are the peak months — expect more visitors and higher prices for tours and hotels.

September is the sweet spot for crowd-free swimming. The water level is still good, the weather is dry, and the tour operators are less rushed. Andorinhas remains swimmable into October and November, though the surrounding lagoons shrink noticeably. If you visit in the dry season, Andorinhas is the one lagoon in the Santo Amaro area that will still look like the photos.

Frequently Asked Questions

How long does it take to visit Lagoa das Andorinhas?

The standard half-day circuit lasts about 3 hours, with roughly 40 minutes at Andorinhas itself. If you want more time in the water, ask your driver to extend the stop — private tours are flexible, and an extra 30 minutes is usually possible for no additional cost.

Is there an entrance fee for the lagoon?

Yes. The national park charges R$10 per person for a three-day visitor bracelet, purchased at the park office in Santo Amaro before you depart. The bracelet covers all lagoons in the park, not just Andorinhas. Fees are subject to change — check the official site for current rates.

Can you swim in Lagoa das Andorinhas year-round?

Andorinhas holds water throughout the year, unlike most lagoons in the park. Swimming is best from June to September, when the water is deepest and clearest. In October and November, the water level drops but the lagoon remains deep enough to swim near its center.

How do I get to Lagoa das Andorinhas from Santo Amaro?

Every lagoon tour includes a 4x4 transfer from your hotel in Santo Amaro. The drive takes 10 to 15 minutes over the dunes. Independent travelers can also walk to the lagoon in about two hours from the park entrance, following the marked trail past several smaller lagoons.