MiscDo you know what circulates at the speed of light on the slope of Collserola?Daniel Romaní16-08-2026
![One of the characteristic sundials of the Porrera Sundial Route, in Priorat.](data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 9"%3E%3C/svg%3E)