Brazil ranks third in total mangrove area around the world, following Indonesia and Australia. Most Brazilian mangroves are poorly studied regarding hydrologic equilibrium mechanisms. Along Mangue de Pedra of Gorda beach, in Armacao dos Buzios, Rio de Janeiro State, Brazil, there is a rare mangrove, which has thrived over a rocky substratum. Of particular interest is the socioenvironmental and historical background of this mangrove amid potential and emerging land use conflicts. A combination of distinct rock units bound together by a geological fault in a semiarid microclimate led to a unique setting in which fresh groundwater from hanging sedimentary rock cliffs mix with seawater creating an unusual small mangrove before a sandy beach. This attractive landscape led to intense property speculation. Sustainable land use by 'quilombolas', descendants of ancient black slaves is being threatened by that speculation, leading to conflicts. Considering the factors and aspects reported above, Mangue de Pedra has high environmental, historicalcultural and scientific relevance and, consequently, should be preserved. Public management measures, however, have not being effective to protect it, leading to a gradual loss of local bio and geodiversity. Solution for this issue includes a set of measures such as creation of a comprehensive environmental protection unit, education and environmental awareness, dissemination of knowledge about the importance of the Mangue, social control and mobilization of the population, based on participation in the decision-making forums, the paradigm shift for UC administration, among others.