Montezuma Well is a sinkhole filled with water and created by the collapse of an underground limestone cavern millennia ago. It is located about ten miles from Montezuma Castle, but is nonetheless part of the overall Montezuma Castle National Monument. There is a constant flow of relatively warm (about 76 degrees Fahrenheit) water with a very high concentration of dissolved carbon dioxide flowing through the sinkhole. Efforts have been made to discover the source of the water flow since the first scuba dive conducted by the National Park Service in 1948. Two natural springs feed it, but the source of those two springs remains a mystery. Because of the high concentration of carbon dioxide in the water, there are no fish. However, the conditions are such that a number of species (including types of insects and leeches, among other creatures) found nowhere else in the world are supported in the unusual environment.
The Montezuma Well is quite large, measuring nearly 370 feet wide and 55 feet deep. More than a million gallons of water flow through it each day. Such a vast amount of water in such an arid environment has drawn people here for thousands of years. There are ruins around the site as well as evidence of ancient irrigation system, portions of which are still in use today. There is a loop trail that takes you to the water’s edge and past a picnic area. You can purchase a combination ticket to the site that also allows entrance to the Tuzigoot National Monument, which is located another fifteen miles north. In turn, the site of these ancient ruins is only about five miles away from the town of Jerome, famous for its reputedly haunted buildings and ghost tours.