Contributor guydrory created this awesome aerial view of one of Portugal's most famous rock formations. It's called the Boca do Inferno, which translates to "Hell's Mouth". It's essentially a seaside cave in the cliffs here where the action of the ocean causes water to shoot out of a mouth-like opening. It's located near Cascasis, a town in the stretch of the coast known as the Portuguese Riviera, west of Lisbon. It has the distinction of being the first cave to have appeared in a movie, a 1896 British silent.