The eyes of Tacacá do Norte’s harried staff widen as yet another customer arrives during the lunchtime rush. The bedroom-sized snack bar can barely hold one line of chairs around its bar but they have somehow managed to squeeze in two. Impatient regulars shake hands and whistle “psst” to the young men staffing the establishment, who gingerly hand steaming pots of shrimp soup and freshly puréed juices over the packed bar.

Arataca boasts a title so extraordinary that, were it more widely known, we would expect the modest Copacabana snack bar to be covered with colorful Nossa Senhora do Bonfim blessing ribbons so that generations of pilgrims could light white, tapered candles and lay baskets of offerings at its sidewalk entrance. That designation is: First Açaí – the Amazonian superberry – served in Rio de Janeiro. Local lore says that the slushy, purple drink was first served here 59 years ago, and it was a hit. Nowadays, you’ll see cariocas all over the city with the drink’s trademark ink-stained teeth. Arataca was opened by two immigrants from the northeastern state of Pernambuco. One was in the military and, in his travels through Brazil, he developed a taste for the highly unique cuisine of the country’s north, particularly that of Pará state, considered the gateway to the Amazon region. Pará is also the cradle of the Amazonian berry açaí, which is sold in barrels at riverside marketplaces in the commercial and political capital of the state, Belém.

In a country the size of Brazil, you’ll have an easier time finding a carioca who’s been to Disney World than to the Amazon region, so cut off is it by vast forests and pricey airfares from the cosmopolitan southeastern cities of São Paulo and Rio. When we visited Manaus and took a days-long boat trip on the Rio Solimões, we introduced ourselves as American, living in Rio. Locals seemed uninterested in asking the usual litany of questions about America but grilled us on Rio, which they had only seen in evening telenovelas.