The Rock Islands of Palau are a grouping of more than 200 limestone and coral islands dotting Palau’s Southern lagoon. These uninhabited islands are famous for their beaches and dive sites. Though it was an overcast day, riding through the soaring limestone cliffs with their emerald green waters was still a gorgeous sight. The rain continued in Palau but it didn't take away from the #1 place I wanted to see on the island - Jellyfish Lake. I took a day trip around the Rock Islands and the highlight was definitely a swim with the million or so inhabitants of Jellyfish Lake. More than 12,000 years old, Jellyfish Lake is filled with millions of migrating golden jellyfish who have evolved over the years without stinging capability due to a lack of natural predators. It is one of several marine lakes like it in Palau but the only one that can be visited. A swim in the lake was featured in two episodes of the TV show Survivor as a reward for winning a challenge. Palau is the only place in the world where it is possible to swim among these harmless prehistoric creatures.