Today’s Wonder of the Day was inspired by Gabriel. Gabriel Wonders, “How are under water caves made?” Thanks for WONDERing with us, Gabriel!

When the air is warm and the Sun is shining down, do you like to go swimming? Whether you're taking a dip in the ocean, a swimming pool, a pond, a lake, or a river, there's nothing quite as refreshing as cool water on a hot summer day.

If you find yourself in Mexico's Yucatan Peninsula during the dog days of summer, you'll want to check out a unique geological feature that doubles as an oasis you'll want to dive into. Let's explore a cenote!

A cenote (pronounced say-NO-tay) is a natural, water-filled sinkhole created when the limestone ceiling of an underground cave collapses. Cenotes can vary in size and shape from deep, vertical shafts to wide pools with underwater caves and passageways.

After the sinkhole forms, a pool of clear, cool, fresh water forms as a result of rainfall and seepage from underground rivers. This is why you'll find thousands of cenotes in Mexico's Yucatan Peninsula.

The entire area is low and flat with virtually no rivers or streams on its surface. Instead, the thick layer of limestone underlying the peninsula features three of the longest underground water systems in the world.

Cenotes throughout the peninsula are the area's main source of water, which explains why they were so important to the ancient Mayan civilization. The name "cenote" comes from the Mayan word "d'zonot," which means sacred well.

The Maya did consider cenotes to be sacred places. In fact, cenotes were believed to be entrances to the Mayan underworld where their gods lived and human spirits went after death.

Today, cenotes are popular tourist destinations. People love to enjoy these natural swimming holes. Cenotes with underwater caves are also great places to snorkel and scuba dive.

Imagine scuba diving into an underwater cavern filled with amazing stalactites and stalagmites. You might also discover treasure on a dive into a cenote.

The Maya often used cenotes for religious, sacrificial purposes. Archeologists have found many interesting things in cenotes, including the fossilized remains of humans, mammoths, giant jaguars, camels, and objects such as gold, jade, and pottery.

Wonder What's Next?

Tomorrow’s eight-legged Wonder of the Day might give you the creeps!