At 2,396 metres on La Palma's summit ridge, the Roque de los Muchachos Observatory is one of the world's premier astronomical research facilities. More than a dozen major telescopes from institutions across Europe and beyond operate here, taking advantage of skies that are legally protected from light pollution by a strict island ordinance — La Palma's "sky law" restricts artificial lighting across the island to preserve observing conditions.
The summit is accessible by road and is open during daylight hours for visitors. The views are extraordinary: on a clear day you can see across to Tenerife, El Hierro, and La Gomera; beneath the observatory the caldera drops 1,500 metres to its floor. In summer the road is above the cloud layer, so you look out over a sea of white cloud with the island's volcanic spine rising above it. The observatory runs occasional open days for public visits to the telescopes; check the Instituto de Astrofísica de Canarias website for dates.
At night, if you camp anywhere on the upper slopes, the sky is remarkable — one of the darkest and most transparent in Europe.