The hike up Morro Dois Irmaos climbs the twin-peaked mountain that frames the western end of Leblon and Ipanema. The reward is one of Rio's great viewpoints: Rocinha and Pedra da Gavea on one side, then the beaches, Lagoa, Corcovado, and the whole sweep of the Zona Sul on the other.
The trail is short but steep and exposed in places, so go early, carry water, and do not treat it as a casual beach stroll. It is best done in clear weather, when the view is the point of the climb.