Prainha is one of the landmark bars of São Luís's reggae circuit, a long-running venue in the historic centre where the sound system thunders on Friday and Saturday nights. The music starts around 10pm and goes until the small hours; the crowd is mixed — students, office workers, tourists who've figured out where to go — and the dance floor fills up completely within an hour.
The beer is cold, the reggae is loud, and the atmosphere is exactly what you'd want from a city that calls itself the reggae capital of Brazil. No airs, no dress code, no cover charge in the early evening. Just a bar that has been doing this for decades and knows how to do it well.