The lava tubes tour at Gruta do Carvão is one of the unique parts of my trip to Azores. Try to make a reservation in advance, either in person or on their website (we couldn't find out how to do it and ended up getting pushed back a couple days because of how popular they are). They only have five tours per day, starting at 10:30am until 3:30pm, and the basic 40-minute introductory ones are €5. If you want a more adventurous activity-filled three-hour tour (excellent for kids), then it's €20. Unfortunately, they don't have anything in the middle.
Our tour guide was so passionate for his job and knew the science behind the lava tubes. He was also personable, engaging, and funny. You see some really cool structures along the cavern walls, such as lateral benches, lava bridges, branching galleries, lava balls, stalactites, stalagmites, columns, spongy lavas, glaze, and tree moulds. This is the place to get your kids' noggins working about archeology! I recommend working this into your trip to the island, especially if you are traveling as a family. read more