Explore the Underwater Caves of Lake Vouliameni
It looks like a volcanic crater filled with blue water, but this lake is also a mineral spa surrounded by beach chairs, umbrellas, restaurants and mystery. This salty lake’s connection to the ocean hasn’t even been discovered, yet. The entrance to the underwater cave opens at the bottom of the lake and extends into the limestone mountains. The cave system goes so deep inside the mountains that it has never been fully explored, even with the use of sonar detection equipment. Inside the cave, the refraction of light and the clear waters make it one of the most impressive natural sights in Athens.