this is the approach to atins. i hired a 4x4 jeep and driver in jeri and we took a couple of days to drive along the coast to atins. atins is the small village right at the entrance of the sand dune national park. it is surrounded by the sea on one side, the vast sand dunes which stretch for miles on the other, the river barreira on the third and unpenetrable marsh land on the last side. it is a poor village, without any infrastructure and almost completely isolated in the middle of this beautiful but human-unfriendly region. the only sure way to reach it, and leave it, is by boat on the river barreira which takes you up to the larger town of barreirinhas. most people who visit the lencois national park enter it along its north shore, via barreirinha. you can get there via the main road to sao luis or via a small plane. from barrieirinhas there are multiple excursions into the sand dune park. atins border the sand dune park along its southern end, where it meets the sea. it is not an easy place to reach, and the reason it can take a long time to drive there along the coast from jeri is that there are no roads, and the drivers have to know exactly when and where the tides will allow passage. if you have the chance however, and like a more raw adventure, do it this way. atins is a gem. barreirinhas is a small big town. the sand dunes down here are virtually deserted and you can hike into them, and across them with the right guides. up in barreirinhas you get to them via 4x4 on daily excursions, and they are full of tourists.