French Guiana borders Brazil to the east and south, while the Maroni and Litani Rivers form the border with Suriname to the west. The majority of the population lives in the Atlantic coastal zone, which has most of French Guiana's limited road network. The coast is mostly mangrove swamp with only a few sandy beaches, and the water along the coast tends to be an unappealing brown in color, due to the vast number of huge rivers emptying into the Atlantic from the Amazon Basin. If that wasn't enough to keep you out of the water, in 2018 swimming was banned at beaches around Cayenne due to dangerous levels of unprocessed sewage. A beach destination this is not, though there's an active and well-protected turtle population that lays its eggs annually between April and July on the beaches around the town of Mana. The densely forested interior, whose terrain rises gradually toward the Tumac-Humac Mountains on the Brazilian frontier, is largely unpopulated, and is home to incredible biodiversity that is nevertheless under threat from illegal gold mining and deforestation.