The cenotes in Mexico are amazing. This one, on private property down a long bumpy road hidden away, was paradise. We had been out visiting Tulum in the morning and the heat was tremendous. Our reward was this little oasis. To get here we climbed down a ladder to a small wooden dock and explored a large enclosed pool. Swallows darted in and out and scuba divers passed thirty feet below us from time to time. Otherwise we had the place to ourselves; all you could hear is dripping water and it was cool crystal clear water. As we swam the ceiling got lower and after a while it opened into a large open cenote where I took this picture. In the middle there is an island of jungle growing out of the rich silty soil.
Canon 1D X, Canon 16-35/f2.8L Mark II
16mm, f4, merged layers of 0.4, 0.8, and 1.6 sec @ 100 ISO