The Olmecs were Native Americans that lived from 1200 BCE to 400 BCE and they are considered the first tribe of the Mesoamerican cultures that followed, including the Mayans and Aztecs.
The Olmecs had a particular reverence for natural places and their religion consisted of being connected to the sky, earth, and underworld. They believed for example that caves were places that connected them to the underworld and the mountains connected them to the sky.