the famous lagoa rodrigo de freitas, in the south of rio de janeiro, is a wonderful example of a naturally occuring phenomenon, right in the middle of the urban sprawl. located between the busy neigbohoods of copacabana, ipanema and jardim botânico, the lagoa is a coastal lagoon that was originally formed by the rise of a large sandbar, eventually seperating the body of water from the atlantic ocean.

like most of such lagoons, the lagoarodrigo de freitas is relatively shallow and very sensitive to changes in the ocean's dynamics, itis fed by some nearby creeks although the salinity remains very high.