after swimming in this lake, but have also known several others who have swam here many times with no problem. Best swimming spots in Lake AtitlanSan Marcos is said to have the cleanest shore for swimming. One type is a more relaxed "dance" type ceremony where participants drink chocolate, dance and mingle, and perhaps go through a few guided exercises together. And if you like the idea of a cacao ceremony, why stop there? San Marcos is the place to be to get your chakras balanced, have a reiki session or participate in a meditation retreat.