The Boa Nova lighthouse, located a few kilometres north of Oporto, is the second-largest lighthouse in the country. It is 47 meters high and came into operation in 1926. The location was chosen considering the dangerousness of the coast in that area – the existence of numerous boulders close to the beach that, submerged at high tide, can escape observation by sailors. It emits groups of three white flashes, with a period of 14 seconds and a luminous range of 52 kilometres.

While walking some days ago near the lighthouse on a very windy late afternoon, I was delighted by the powerful three light rays emitted by the lighthouse contrasting with the bluish sky and the darkness of the falling night. The lighthouse came into operation after sunset. Still, I had to wait for it to become dark enough so the light rays could be clearly observable and recorded with my digital camera. I had to use a sturdy tripod to be able to photograph in such windy conditions at low speeds.