Flamingo Mexicano de Celestun Natural Park - On the boat trip up the saltwater estuary, you'll see flamingos standing around in groups in the shallow water, along with cormorants, egrets, osprey and herons. When the flamingos spread their wings to take flight, this is something you don't see in the zoo. Look for the baby flamingos that are gray with black tipped wings. The boat also glides through the channels lined with mangrove trees that feel like the "Lost World." You'll see huge termite's nests in the trees. Bring your swimsuits along to take a dip in the fresh water spring.