Gruta da Malha is one of Terceira’s lesser-known volcanic caves, hidden near the village of Biscoitos. Unlike the more famous Algar do Carvão or Gruta do Natal, this cave is much smaller and feels more intimate, almost like a secret corner of the island’s volcanic world. Inside, you’ll see dark basalt walls formed by ancient lava flows, a raw reminder of how the island was created.

What makes Gruta da Malha interesting is precisely its scale and simplicity. It’s not a grand spectacle but rather a glimpse into the underground geology of Terceira. Visiting here gives you a sense of discovery — the kind of place that many travelers miss, but which tells the same volcanic story in a quieter way.

The best time to visit is during the daytime, when there’s enough natural light at the entrance to guide you. Unlike the larger caves, it isn’t set up with full tourist infrastructure, so it feels much more natural and untouched.

Accessibility is fairly easy: it’s located near Biscoitos and can be reached by car with just a short walk from the road. You don’t need to hike long distances, but it’s best to bring good shoes, since the floor is uneven and can be damp.

I would describe Gruta da Malha as a hidden gem. It won’t impress with massive chambers or dramatic tours, but for travelers who enjoy stepping off the main trail and seeing something raw and authentic, it’s a rewarding stop.

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Some of the stunning photos featured in this guide were generously shared by Bruno Ázera, an incredible photographer and local from Terceira Island. Make sure to follow him on Instagram! And if you're looking to dive deeper into the best photo locations across the Azores, he has an outstanding photo guide to the archipelago, available at the following link.