The Rio Sucio or "Dirty River", where one branch is colored yellow/brown by the minerals it carries from the Irazu Volcano, is seen mixing with the clear waters filtered by the tropical rainforest in the Braullio Carrillo National Park, 50 km (31 miles) east of San Jose, June 5, 2012. According to a recent poll, Costa Ricans would agree to pay higher taxes if it is used for actions to promote the environment, according to local media. Costa Rica, with more than 30% of its territories held in national parks, celebrates World Environment Day today. REUTERS/Juan Carlos Ulate (COSTA RICA - Tags: ENVIRONMENT SOCIETY)