I come here often to pray to the water, somewhat like when one goes to Lourdes or the Chalice Well in the UK.
It is called Montezuma Well, but it has nothing to do with the Aztec Emperor Montezuma.
It is a collapsed limestone pit filled with water, a sinkhole. No one knows where the water comes from. The water is a constant 74 degrees F. I don't recommend drinking the water, as it has a concentration of carbon dioxide that is 600 times higher than most aquatic environments.
The only critters that live in there are leeches, water scorpions and turtles!
The Sinagua, a prehistoric people used this water to irrigate their crops of corn, squash and beans . They lived and prospered here from approx. 900 bce to 1400 ce.
"The constant supply of warm, 74 degree water was the life-blood of the people who made their home here. Over 1.5 million gallons of water flows into the Well every day, a rate that has not fluctuated measurably despite recent droughts throughout the state of Arizona. This water enters a "swallet" near the end of the trail into the Well and flows through over 150 feet of limestone before re-emerging from the outlet into an irrigation ditch on the other side. Sections of this ditch date back over 1,000 years. The value of this water is recognized still today, as many residents of nearby Rimrock, AZ, rely on water flowing through the irrigation ditch for their gardens and livestock." Source:
https://www.nps.gov/moca/planyourvisit/exploring-montezuma-well.htm
For more information on the Sinagua people, click here:
http://www.mesacc.edu/~thoqh49081/StudentPapers/sinagua.html
More info on Montezuma Well:
https://www.desertusa.com/desert-arizona/montezuma-well.html