One of the best places for young people to hang out in Rio is the Lapa neighborhood. At night, the locals gather around Arcos da Lapa aqueduct. There are a lot of bars and clubs in the area, but most people prefer to hang out and drink beer in the cobble-stoned side streets of this neighborhood. Sometimes it is just too hot to be inside, especially when few bars and clubs have air conditioning. You can buy beer or water from street vendors. There are also bars that will allow you to bring your drinks outside.
I would not advise staying here too late. When the crowd thins out, you should probably hop in a taxi and go back to your hotel. This goes for any place in Rio.
Located under the architecturally sound Arches (Roman Aquaducts) of Lapa, are some of the loudest Samba drums in all Rio.
I'm referring to a night fiesta which takes place on Fridays under the arcos and tests the foundation to its very core. The drums are loud, it's hot and sweaty, the music pulsates and people gyrate, the whiff and aroma of open-air kabab vendors inflames the olfactory senses and all else just comes together courtesy the alcohol. There were these samba drum players along with some other musicians playing different instruments who started a major jamm session right under the arcos and got everyone in the mood. They were completely impervious to the crowd watching them, everyone was dancing and these guys were having a blast themselves I mean one of them let me play the drums while he went to get a drink and do some dancing of his own. Real cool stuff.
I'm not certain if this party is all the year round but I know it's definately there during the summers. A local friend Claudio took us there and do I owe him big time.
Dress Code: I remember that there was a small inclining park on one side of the street cause some people where passed out there. Also on the other side under the arches the street narrowed into an alley and then there was a deep end and a wall. I say all this cause i'm not sure of the exact location. There was a club / garage a little down the street that was full of people listening to local samba prodigies just going at it and everyone was soo in the mood. It was an almost entirely locals only affair.