Chichen Itza has the most impressive Mayan ruins in Mexico, including El Castillo pyramid and Tzompantli (Temple of Skulls).
Cenote Ikil, or "Sacred Blue Well", is one of nature's works of art. Sunshine and water pour into the limestone sinkhole as bats and swallows dash in and out. It is 60 m in diameter and 40 m deep, while the cave opening is 25 m above.
The good news is that I can not only admire it, but also go snorkeling. The water is refreshing and cold. Swimming toward the vines and waterfalls, I can see black catfish nuzzling around the roots of various plants.
Looking up, I feel serene, as if I am in a grand cathedral.
Cenote Ikil is one of more than 8,000 cenotes, or sinkholes, in Mexico's Yucatan Peninsula. Filled mainly by water from underground rivers they nurtured Maya civilization from AD 250 for about seven centuries.
Ancient Mayans believed some of these cenotes were gateways to the afterlife and threw valuable items and even human sacrifices into them.
Not far away from Cenote Ikil is the famous Cenote Sagrado, also known as the "Sacred Well" or "Well of Sacrifice", in Chichen Itza.
From 1904 to 1910, American diplomat Edward Herbert Thompson dredged the cenote and discovered gold artifacts, jade and pottery. He also found human remains, possibly confirming legends that told of sacrifices to the rain god.
The cliffs around it are vertical and the water is murky green. It looks deep and lifeless and is part of a tour of the grand ruins of Chichen Itza.
Cenote Ikil is a perfect getaway from the scorching sunshine.
A two-hour drive from Merida, the capital of Yucatan, or Cancun, Chichen Itza was the capital of one of the most powerful ancient Maya city states.
Named one of the "new seven wonders of the world" in an online poll in 2007, alongside our Great Wall, and listed as a World Heritage site, it is the most famous, studied and visited Mayan ruins in Mexico.
Its landmark is El Castillo, or the Castle of Kukulcan, a massive temple palace rising 30 m from the ground in the center of a grassy plaza that was built between AD 650 and 800. What makes it a wonder of the world is not its height and history, but the intelligence that went into building it.
The pyramid shape is actually a huge Mayan solar calendar made of stones. Its four sides each have 91 steps which, added to the top platform, makes 365, the number of days in a year. On each face of the pyramid are 52 flat panels, symbolizing the 52 years in the "Calendar Round".
Most amazing of all, around March 21 and Sept 21, the setting sun forms a series of triangles on two of these 91-step stairways that look like "the feathered serpent" god Kukulcan.
You don't need to know much about the technical details of its construction, however, to enjoy its brilliance.
At the northwestern corner of the main plaza, Principle Ball Court is the largest Mesoamerican ball court in the world. It is 149 m long and a game called poktapok, a sort of medieval soccer, was played there. Two teams of seven had to knock a rubber ball through a pair of stone hoops built on two almost vertical side walls, 3 m above the ground. The challenge was to score using just your hip.