This book explores many mysterious features of the structure and evolution of the Earth's continents, still unknown to the scientific community and a wider audience. Science has now proved that the southern continents of South America, Africa and Australia represent the southern ends of a single three-beam megacontinent. It began to form 4.4 billion years ago in a huge three-beam cavity on the planet's surface and grew vertically up to its present state. Proof of the reality of a single three-beam megacontinent is a fundamental discovery in Earth sciences, and represents a new level in the understanding of the planet's structure. The text will appeal to researchers of Earth sciences, university teachers and students, and secondary school teachers of geography and geology, as well as all readers with an interest in the history of our planet.