Teide casts the world's largest shadow projected on the sea. This phenomenon occurs during sunset, and also causes the shadow to partially cover the island of Gran Canaria or La Gomera at dawn, more than 40 km away from the mountain. One characteristic is that the shadow has a perfectly triangular shape, even though Teide's silhouette does not; this is an effect of perspective. Visitors and tourists climb to the top of the volcano at sunset to witness this phenomenon.