Diary of a Voyage Made in 1781 from the Rio Negro to Discover the Bay of Todos los Santos, the Buen Suqueso Islands, and the Source of the Colorado River is a fascinating multi-genre book by Basilio Villarino. This documentary tells the story of a journey along the river, research discoveries and interactions with local cultures. Villarino describes in detail the scenery, adventures and experiences of the trip, allowing readers to feel the atmosphere of the time. This book is not only a document of a historical journey, but also an important reflection on the interaction of man with the environment and culture.