The light in Rio is spectacular, especially on the beach. Take a walk from Arpaodor to Leblon which takes about 45 minutes. Do this when the sun sets. It sets just behind the Dois Hermanos (two brothers) and the light is light blue/pink most of the time. The sound of the waves, people and Ipanema to your right make this a very special walk and keeps you fit. In the morning the sun comes up from Copacabana, so a walk from Arpoador - do check out the fish market - towards the Copacaban Palace is lovely too. Locals doing morning exercise, fishing boats coming back. I want to be there now!
Arpoador>Leblon Arpoador>Copacabana