Lagoa do Peri is a freshwater lagoon located on the southern end of Ilha de Santa Catarina, within the boundaries of the Parque Municipal Lagoa do Peri, a protected conservation area. It is the largest freshwater lagoon on the coast of Santa Catarina and serves as the primary drinking water source for the southern portion of Florianópolis. The lagoon has received the Blue Flag certification ten times, reflecting its notably high water quality. The water is clean and clear.

For paddlers, the lagoon offers calm, flat water well suited to kayaking, canoeing, and stand-up paddleboarding. The experience is generally low in technical difficulty, making it accessible to beginners and families, including children as young as two years old when accompanied by an adult. Guided tours typically launch from the southern edge of the lagoon, accessed via Rua Euclides João Alves in the Armação do Pantano do Sul neighborhood, near kilometer 42 of Rodovia SC-406 heading south. This is distinct from the main lagoon entrance. A typical guided paddle covers approximately 4 kilometers round trip and lasts around four hours, including time ashore.

From the water, paddlers can explore the lagoon's shoreline and then transition into smaller tributary channels where the Atlantic rainforest closes in densely on both sides. These narrower passages offer close encounters with diverse birdlife, large blue morpho butterflies, and caimans along the banks. Toucans and small primates inhabit the surrounding forest. A short hike from the water leads to the Cachoeira da Gurita waterfall. The surrounding hillsides are covered in primary Atlantic rainforest, one of the last remaining fragments of this ecosystem on the island.

As a protected natural monument, the lagoon is subject to conservation regulations. Motorized boats are not permitted; only non-motorized craft such as kayaks, canoes, and SUPs are allowed on the water. Life jackets are mandatory on guided tours. Accommodations are available in the nearby communities of Armação and Morro das Pedras. The conservation project "Lontras," focused on protecting otters, coatis, raccoons, and other species, operates at the lagoon and accepts advance-booked visits.