One of Rio’s most traditional and notorious neighborhoods, Lapa has had many incarnations. It was originally a beach (known as the “Spanish Sands”) before being paved over and made into a rather posh 19th-century residential neighborhood. The Passeio Público (Rua do Passeio Público, Lapa, 7:30 a.m.–9 p.m. daily) evokes what Lapa must have been like when it was still a swank bairro where well-to-do families strolled beneath the shady trees of this elegant park.

By the turn of the 20th century, Lapa’s fortunes had declined. Middle-class families migrated south, and a colorful collection of gangsters, tricksters, low-lifes, prostitutes, bohemians, and sambistas started moving in. They created a wildly bohemian underground scene that become the stuff of Carioca legend.

During the 1930s, Lapa was not unlike New York’s Harlem. However, as the century wore on, buildings became increasingly dilapidated and disreputable, and crime escalated. Until a decade ago, the neighborhood was very down and out.

Then, unexpectedly, a renaissance began to take hold of Lapa. Nightly samba jams were held beneath the arches of Lapa’s colonial aqueduct. A row of antiques stores opened along the Rua do Lavradio. Inspired by Barcelona’s Gaudí, a Chilean artist named Selarón began covering a steep 215-step staircase to the neighborhood of Santa Teresa with a bright mosaic of ceramic plate fragments (many sent to him from all four corners of the globe).

But most of all, Lapa became famous for its intensely vibrant nightlife, where Cariocas from all walks of life congregate to eat, drink, and dance the night away.

Although Lapa’s fortunes have recently taken a turn for the better, it is still somewhat seedy around the edges. During the day, it’s quiet, and even a bit deserted in places. At night, although its main streets are teeming with people, it’s potentially dodgy if you don’t take care (and cabs). Nonetheless, it’s a wonderfully atmospheric slice of old Rio that shouldn’t be missed.

Lapa’s most iconic landmark is the Arcos da Lapa. Originally known as the Aqueduto da Carioca, this distinctly Roman 42-arch aqueduct was built in 1750 to supply fresh water from the Rio da Carioca to the residents of Centro. In 1896, it got a new lease on life as a viaduct over which bondes (trams) transported passengers to the elegant hillside neighborhood of Santa Teresa.