Mate Leão is a traditional Brazilian iced tea that is widely consumed in Rio de Janeiro. It is made from yerba mate leaves, which are steeped in cold water and then sweetened with sugar or honey. Mate Leão is known for its unique flavor, which is slightly bitter and earthy. It is a popular choice for those looking for a non-alcoholic and refreshing drink in Rio. You can find Mate Leão in supermarkets, cafes, and even street vendors throughout the city.