This is the lagoon as seen from Pico do Corcovado (Christ Statue). The strip of land is Barra Da Tijuca west of Rio proper as the crow flies. The brochures found at Pico do Corcovado claim the christ statue faces a similar statue in Portugal, in perfect true compass alignment actually which is pretty remarkable for the time before true compasses.
The islands in the background are Ilhas Tijucas. Tijucas is an old Indian name of the indigeneous people of Rio before settlement.