When the weather is nice, come visit one of the first public parks built in South America. It features classic landscaping and architecture and feels like stepping back in time. It is also a wonderful place for relaxation after a long day of e.g. sunbathing. And a great place for a picnic since the trees provide enough shade.
Wikipedia https://en.wikipedia.org/wiki/Passeio_Público
Address (Unnamed Road), Rio de Janeiro, Brazil
Coordinates -22°54'48.311" N -43°10'35.655" E