Visit the Blue Lagoon on Mafia, There is a huge natural swimming pool called the Blue Lagoon that changes color with the tides. The Blue Lagoon is a great place to visit if you’re staying on Mafia for a few days. It’s near Juani Island in the Mafia group. To get to this one-of-a-kind spot, you can take a boat through a waterway lined with lush green mangrove trees. Many small islands are to your left, and Juani Island is to your right. The Blue Lagoon’s water is shallow, making it a great place to swim and explore.