Aracaju is the capital of Sergipe, the smallest state in Brazil, and one of the most relaxed state capitals in the northeast. It is a planned city, laid out in a grid in the 1850s, with a long seafront at Atalaia beach where most visitors stay, eat and walk in the evening.
Aracaju will not detain you for long, but it is a pleasant stop between Salvador and Maceió. The Orla de Atalaia has bike paths, a small oceanarium run by the turtle conservation project Tamar, and the Passarela do Caranguejo, a street of restaurants serving the city's speciality: crab, cracked with a small wooden mallet at the table.
The best trips are out of town. South, the Rio Vaza-Barris estuary has sandbanks and mangroves reached by boat, with the Ilha dos Namorados and the Crôa do Goré sandbar. North-west, three hours away, Canindé de São Francisco is the base for boat trips into the São Francisco canyons. São Cristóvão, the state's first capital, has a UNESCO-listed square half an hour inland.