Mount Teide volcano, Tenerife, Canary Islands. Its 3,718-metre summit is the highest point in Spain. Like the other Canary Islands, and volcanic ocean islands in general, Tenerife was built by accretion of three large shield volcanoes. 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.
