Arraial do Cabo is a municipality situated in the Brazilian state of Rio de Janeiro, positioned within the Lakes Region near Búzios. It occupies a total area of 160 square kilometres and is defined by its coastal geography along the Atlantic Ocean. The town serves as an important administrative center for this specific stretch of coastline, leveraging its natural harbor and proximity to significant marine environments to support local governance and tourism infrastructure.

The settlement was founded in 1503 by the explorer Amerigo Vespucci, establishing a long historical presence in the region. Its strategic location made it a dangerous point during the age of sail, resulting in numerous shipwrecks from the arrival of the Portuguese Navy through the nineteenth century. This maritime history, combined with rich biological factors, contributed to its reputation as the Dive Capital. In 1960, the local fishing industry was documented in a film directed by Mário Carneiro and Paulo Cesar Saraceni.

The municipality is characterized by stunning beaches and protected natural reserves that define its landscape. Key sites include Praia do Grande, the largest beach with cold waters, and Praia dos Anjos, which features a marina and restaurants. The area contains the Ilha do Cabo Frio Biological Reserve and the 56,769-hectare Arraial do Cabo Marine Extractive Reserve, created in 1997. Notable landmarks include the Grota Azul, known for its intense blue waters, and the rock formation Pedra do Macaco.

Visitor appeal centers on diving, snorkeling, and boat tours departing from Praia dos Anjos to nearby beaches and viewpoints. The town offers spectacular views from lookout points like Ponto de Observação dos Pescadores and Mirante do Pontal to Atalaia. Cultural highlights include the Igreja Sagrado Coração de Jesus and Igreja Nossa Senhora dos Remédios. The local economy benefits from tourism, with numerous dive schools and hotels catering to international visitors seeking clear turquoise waters and surfing opportunities.

The population was recorded at 30,593 in the 2020 census, though other sources cite figures around 32,822 for 2025. Access is facilitated by the Cabo Frio airport with flights from Belo Horizonte and Rio de Janeiro, or by road via the Ponte Rio-Niterói. Public transport includes buses from Rodoviária Novo Rio in Rio de Janeiro. The climate supports year-round tourism, with high season crowds concentrated on weekends, particularly at popular diving spots and beaches.