Lagoa de Piratininga is a coastal lagoon located in the Piratininga neighborhood of Niterói, in the state of Rio de Janeiro. It offers approximately 4,130,000 square meters of navigable water suitable for small craft, making it a substantial body of water for paddling. The lagoon is connected to the sea via the Canal de Itaipu, which sits between Camboinhas and Itaipu beaches; paddlers visiting this canal area will notice the tidal influence where rising tides bring seawater into the lagoon.

The shoreline extends roughly 10.6 kilometers, and much of this perimeter has been developed as the Parque Orla Piratininga, a linear park featuring 17 access plazas distributed along the lagoon's edge. These plazas serve as natural put-in and take-out points and include piers that extend over the water. The park also incorporates dedicated support structures for artisanal fishing, including boat storage areas and fishing piers, which reflect the lagoon's long-standing role as a working waterway for local fishermen. Paddlers should be aware of fishing activity along the margins.

A continuous pedestrian and cycling path runs along the lagoon's shore, and the park infrastructure includes a viewpoint on the Ilha do Pontal. The Eco Cultural Center, located within the park, provides a landmark reference point along the route. Access to the lagoon is available by car or public transport, with several bus lines serving the area; parking can be limited during peak periods.

The lagoon supports notable biodiversity, and the surrounding ecosystem is home to diverse wildlife. Sanitation concerns have been noted by visitors, which may affect water quality in certain areas, and prospective paddlers should factor this into their planning. The lagoon is suitable for small craft such as kayaks and canoes, and the relatively sheltered nature of the water makes it ideal for recreational paddling.