Gruta do Natal (Christmas Cave) is a captivating lava tube located in the heart of Terceira’s volcanic interior. Stretching for nearly 697 meters, this horizontal cave was formed by ancient lava flows and offers a unique, immersive underground journey through the geological history of the Azores. Named after a Christmas mass once held here, the cave carries both cultural and natural significance.

Why Visit:

• Walk inside a real lava tube shaped by flowing molten rock

• Discover dramatic rock textures, rope-like formations, and lava stalactites

• Visit the on-site interpretation center to learn about the region’s volcanic past

• Experience a serene and mystical atmosphere unlike any other cave on the island

Interesting Facts:

• The cave’s maximum height is 12 meters, and its width can reach up to 7 meters

• Cultural events such as religious ceremonies were once held here, giving the cave its name

• Located in the same volcanic region as the Mistérios Negros trail and Lagoa do Negro

Access & Opening Hours:

• Easily accessible by car; located just a short drive from Algar do Carvão

• Open seasonally:

  • June–September: daily, 14:00–18:00

  • April–May: daily, 14:30–17:00

  • October–March: Tuesdays, Wednesdays, Fridays, and Saturdays, 14:30–17:00

• Tickets: €9 solo or €15 combined with Algar do Carvão (currently under renovation)

• Managed by the Montanheiros Association: www.montanheiros.com

Why It’s Worth Visiting:
While Algar do Carvão may be Terceira’s most famous cave, Gruta do Natal offers a more intimate and contemplative underground experience. Its horizontal path is easier to explore, and the lava formations tell a fascinating story of the island’s volcanic evolution. If you're looking for a peaceful, otherworldly cave that blends geology with cultural charm, this is the place to go.

Insider Tip: Pair your visit with the nearby Mistérios Negros hike or Lagoa do Negro for a full inland volcanic day trip. Bring a flashlight if you want to examine the cave walls in more detail — though the main path is softly lit, deeper textures often go unnoticed without extra light.