Some of the world's most recognizable natural landmarks are monoliths. Uluru (pictured) and El Capitan are so well-known that tourists plan their itineraries around them.
These massive stones were formed in prehistoric times by violent eruptions, tectonic shifts or eons of erosion. Some are still surrounded by legends, while others are pilgrimage sites or considered so sacred that it is a sin to set foot on them. All are stunning examples of the kind of architecture that Mother Nature is capable of.
Here are some of the world's most impressive monoliths.