Sumidero Canyon is outside of the city of Chiapa de Corzo in the state of Chiapas in Mexico.

We took a guided boat tour along the Rio Grijalva. The river is 22 miles in length and the sheer wall of the canyon reach almost 4,000 feet high. We saw herons, egrets, cormorants, vultures, kingfishers and crocodiles. The guide called attention to points of interest, such as the underwater caves and the "Christmas Tree." My photo is crummy, but the cliff face, which is covered in moss, is supposed to look like a Christmas tree.