I walked to the Vista do Rei viewpoint just before seven in the morning, before the tour buses arrived, and the caldera was full of cloud. Not obscured by it — full of it, the way a bowl fills with milk. Then a wind came through and the cloud tore apart in slow strips and underneath were the lakes, one distinctly blue, one distinctly green, in a silence I could feel in my chest. I stood there long enough that my coffee went cold without me noticing.
The scientific explanation for the colour difference involves algae concentrations and the way the two lakes interact with different light angles. The local explanation is a legend about a princess and a shepherd who loved each other and wept until their tears became the lakes, each keeping the colour of their eyes. I prefer not to choose between them.
The village of Sete Cidades sits at the bottom of the caldera, on the isthmus between the two lakes. It is one of those places that feels like it exists at the bottom of a dream — a church, a handful of houses, a road that goes along the water and then stops. I had a coffee at the single café and the owner, an older woman who spoke no English and my Portuguese at speed, pointed proudly at a framed photograph on the wall that turned out to be António Salazar. I nodded in what I hoped was a neutral way and ordered another coffee.
Walking the caldera rim is the thing to do here, and it takes most of a morning if you’re not rushing. The trail moves through eucalyptus and Japanese cedar, through pasture where cows stand in the mist looking philosophical, and along cliff edges where the drop to the lake surface is sudden enough to quicken the pulse. On one stretch I was walking alongside a hedge of hydrangeas so blue they looked artificial, the kind of colour that shouldn’t exist at this scale in nature.
The swimming is possible in the larger Lagoa Azul — cold, algae-soft water, the caldera walls rising on every side. I swam out to the middle and floated and tried to imagine what this place looked like before the crater filled. It didn’t help. Some geographies resist rational thinking, and Sete Cidades is one of them. The scale is wrong in a way that makes your sense of perspective feel unreliable. It’s good.
When to go: June and July for the hydrangeas in full bloom along the rim trail. Early mornings year-round reward patience — the cloud inversions that fill the caldera at dawn clear by mid-morning, and the window between the two is worth setting an alarm for. Avoid midday in summer when coach groups cluster at Vista do Rei.