Welcome to the course “Seismic tomography: Look inside the Earth”. We will speak about the use of seismic tomography and its mathematical base, we’ll learn about earthquakes and find out how they start, also we’ll conduct some experiments and go on an expedition to Kamchatka. By the end of the course you’ll know the basics of seismology and how to use the technical instruments and programs in practice. So it doesn't matter what level you’re on. Complex things are explained with simple and accessible language. Geophysists, mathematicians, geologists, geochemists, petrologists, engineers and everyone interested will find a lot of new information and get the access to the author's research methods and scientific algorithms that are used by seismologists all over the world. The adventure begins!