"In het Hol van den Leeuw: Reisschetsen uit Sovjet-Rusland" is a book by the famous Dutch traveler and journalist Jan Fabius, where the author shares his impressions of his travels in Soviet Russia. In this book, Jan Fabius talks about his observations and impressions from traveling primarily through Ukraine, but also through other regions of the Soviet country. He describes what he saw with a high level of detail and depth, demonstrating his understanding of the cultural, historical and political aspects of life in Soviet society. This book became an important document of international dialogue, as well as a source of important data for the study of Soviet history and culture.