Earth Pyramids. These spires are an example of a landform known as hoodoos. They are composed of unconsolidated material deposited by glaciers during the last Ice Age. Each pillar is capped by a piece of rock that protects it from erosion. The unprotected material is eroded by rains, gradually forming a spire. Hoodoos form over long periods of time in sites sheltered from winds and in areas that have experienced varying periods of aridity and humidity. Photographed in Renon, South Tyrol, Italy.