Onyx cave, located within Coronado National Forest, is considered to be the finest cave in Arizona. Helictites and speleothems, such as shields are numerous and beautifully developed.
Year designated: 1974
Please remember, National Natural Landmarks (NNLs) are not national parks. NNLs are owned by a variety of public and private entities and allowing visitation is at their discretion. Many NNL sites maintain public websites where additional information may be found.