in ipanema, numbered eight to ten, postos are often used as markers for people to meet friends. posto 9 is right across from vinícius de moraes street adjacen to posto 8 which, as the rainbow flags suggests, is the gay beach - somewhat of a recent pioneer of carioca liberal thinking. 

posto 9 has long been regarded as the trendiest part of the shoreline, and is famous for alternative gatherings, liberal political views, and mostly beautiful young crowds.