Rio de Janeiro, or as it is commonly called, Rio, is home to the Sambadrome, where thousands of participants and onlookers check out Carnaval's best samba performances and costumes every year in February or March (the date moves in tandem with Holy Week). It's also a populous, active city with thousands of people taking the metro (which is convenient, but doesn't serve the whole city, leaving Ipanema somewhat unconnected) and the many urban buses. It's also where many locals and tourists take the bondi (a mix between a train and a funicular) up through tropical rainforest to visit the spread-armed statue of Cristo Redemptor (Christ the Redeemer), many of them spreading their arms in emulation of the statue.
Many tourists stay in either beachfront Ipanema or Copacabana, where frosty açaí (the fruit of a palm tree, made into a frozen snack) is served at beachfront stalls, and the middle-eastern sandwich and juice shops will keep you topped up most of the day. Nightlife is wild in this part of the city, with discos and bars filling up late and spilling out into the streets in the wee hours. It's pretty common to find your whole hostel room has slept through breakfast and many of them, through lunch. A great way to get your energy up before a night out on the town is a rodizio (literally: rotation, in this case, an all you can eat buffet, often featuring meat).
Most people come to Rio for the beaches, the nightlife, the Maracaña soccer stadium (and games), a few iconic photo ops, and all the caipirinhas they can drink, but sleepy Santa Teresa (the artist-colony hill neighborhood accessible by trolley), botanic gardens and the ground-level favela tours also have their fans. Wherever suits you, enjoy what Rio offers, but follow the Cariocas' (Rio-dwellers), example and keep an eye out for your surroundings. Find articles on Matador about six fun things to do in Rio, and another on hangliding over this Cidade Maravilhosa (wonderful city, its nickname).
Photo Phillie Casablanca