Gallery 0 Results Reset search Close Ramsar Convention Secretary General, Martha Rojas-Urrego, visting Sian Ka'an Ramsar Site CONANP Mexico Sian Ka'an lies on a large karstic plain along a 120km-long barrier reef. Two large, shallow bays surrounded by mangroves, as well as numerous sinkholes or cenotes, are main landmarks in a landscape of tropical deciduous forests. CONANP Mexico