Los Jameos del Agua - Lanzarote

“Los Jameos del Agua” was created in a collapsed section of a volcanic tube and is reportedly the largest submerged volcanic tunnel in the world. Spanish artist César Manrique turned it into a nightclub and underground pool in the 1960s. There is even a concert hall and restaurant and bar built into the tunnel. The cave system displays stalactites and stalagmites and is home to a unique species of blind white crab that have adapted to the tunnel's darkness.