The Rio Jucu is one of the most significant rivers in Espírito Santo state, originating in the Serra do Castelo near Pedra Azul in the municipality of Domingos Martins and flowing approximately 180 kilometers before emptying into the Atlantic Ocean at Vila Velha. Its two principal tributaries are the Rio Jucu Braço Norte and the Rio Jucu Braço Sul. The river supplies water to roughly 25% of the state's population, making it a critical resource for the greater Vitória metropolitan region.

The river's character varies considerably along its length. In its upper reaches it runs fast with frequent rapids, rated from Class I to Class V+ under normal water levels, with the possibility of reaching Class VI during the rainy season. This makes it a destination for whitewater rafting and kayaking across a wide range of skill levels. Where the river meets the Atlantic at Vila Velha, tidal influence during high tide produces a small tidal bore effect.

A well-established paddling route runs through the municipality of Viana, covering approximately 10 kilometers between Pedra da Mulata and Jucuruaba. This stretch takes roughly two hours to complete by kayak and passes through areas of preserved forest. Wildlife along this corridor includes capybaras, birds, and other fauna typical of the Atlantic Forest biome. The Viana municipal government has been developing this route as part of a formal adventure tourism program, with guided kayak trips offered at R$100 per person on scheduled dates.

The estuary at Vila Velha lies within the Jacarenema Ecological Reserve, a 307-hectare conservation area where mangroves line the riverbanks. This lower section has experienced pollution from wastewater and garbage carried downstream from upriver areas. Water quality is a known concern throughout the river's course, and at least one long-running paddling organization suspended its annual descent from Jucuruaba to Barra do Jucu due to excessive pollution levels. Paddlers should verify current water quality conditions before planning any trip, particularly for routes in the lower and middle sections of the river.

The river holds considerable historical importance as the waterway that enabled early exploration of the interior of what are now the municipalities of Vila Velha, Cariacica, and Viana. Its name derives from an indigenous word for a cinnamon tree.