On the rugged northwest coast of Sal, the Blue Eye — Olho Azul — is a flooded lava cave connected to the sea that glows a startling blue when the light is right.
How the Blue Eye works
When the midday sun shines through an opening in the rock and reaches the water, the cave lights up an intense blue in the shape of an eye. It's a genuinely striking natural phenomenon — but it only appears under the right conditions.
When to go
Visit on a sunny day between about 11:00 and 13:00, when the sun is high; on a cloudy day you'll see little. The site is on rough terrain, so a quad or 4x4 is the best way to reach it. Take care near the swell, and note there's a natural rock pool nearby where you can also swim.
📍 Northwest coast of Sal (Buracona) · 🕐 Best 11:00–13:00 · 💰 Around €3 per person (subject to change).
When the Blue Eye actually 'works'
The famous electric-blue glow is a light trick: the sun must shine down the underwater cavity at the right angle, which happens roughly between 11:00 and 13:00 on clear days. Outside that window — or under cloud — the Eye is simply a dark pool, and visitors who arrive at 15:00 wonder what the fuss was about. Time your visit, and accept that the Atlantic sometimes refuses to cooperate.
Buracona beyond the Eye
The surrounding site is worth the trip in itself: a black lava shelf pounded by open-ocean swell, blowholes that erupt with the bigger sets, and a large natural pool where confident swimmers can bathe when conditions are calm — heed the attendants, because the swell here has real power. The drive up the wild north-west coast, past Palmeira, shows you the empty, elemental side of Sal.
Practical information
- Small entry fee; simple café at the site.
- Roughly 40 minutes from Santa Maria; included on nearly every island tour.
- Swimming in the pool only in calm conditions — never near the blowholes.
- Sturdy sandals help on the sharp lava.
- Combine with Palmeira for lunch — see our Palmeira guide.