Get an early start and depart from San Ignacio at 7:30 AM. Drive out to St Herman's Blue Hole National Park, known for its lush rainforest and intricate system of interconnected caves and azure freshwater pools. Begin your adventure through the park with a rainforest hike that will end at the entrance to the Crystal Cave system.
Embark on a spelunking expedition through the series of limestone caverns that the Mayans treated as a natural pantheon. Admire the beautiful stalactites, stalagmites, flow stones, rock columns, crystalline formations, and Mayan artifacts adorning the interior of the caves.
Let your guide show you the evidence of ritual ceremonies that took place thousands of years ago, including pottery, fire pits, charcoal ash, and human remains. Step into Wonderland, an aptly-named chamber deep in the earth with walls covered in shimmering crystals. Spend anywhere from 3–5 hours exploring the cave depending on your energy.
Let your guide know if you want to eat the packed lunch and get some rum punch inside the cave or back at the parking lot and fill up after a long day's trek. Finish off with a refreshing dip in the Blue Hole pool the park is named for. Arrive back in San Ignacio around 5:30 PM.