Angra do Heroísmo, Italy
Gruta do Natal (Christmas Cave), also known as Galeria Negra or Gruta do Cavalo, is a cave system in municipality of Praia da Vitória, on the island of Terceira in the Portuguese archipelago of the Azores.
Listen to the audio guide for Natal Caves Free on WIP — starts by itself when you arrive, even with the screen off