The Monte Arci Geomuseum is located in the historic center of the city of Masullas and is located inside the seventeenth-century convent of the Capuchin Friars. The Geomuseum is a Mineralogical and Paleontological Museum and is built from more than 400 finds of very ancient origin. The exhibition is located in the ancient cells of the Capuchin Friars. The finds trace the evolution of the “Arci” volcano which gave rise to obsidian, sold and marketed as early as the Neolithic. The collection features unique minerals in the world, volcanic rocks, precious crystals and extraordinary fossils. The exhibition is divided into five different rooms. The first is the Flù room: a dark room in which the spectacular phenomenon of mineral fluorescence is shown thanks to Wood lights. The minerals on display reveal their colors and their hidden nuances, giving a unique experience. The Volcanic Room tells, through films and 3D reconstructions, the climate and life that characterized the Miocene, 20 million years ago, in the area of Monte Arci. The corridor leading to the Volcanic Room offers a large exhibition of fossil organisms that lived 20 million years. Large blocks of coral, sea urchins and shells will immerse the visitor in the forming Mediterranean Sea. The history of the “Arci” Volcano is told mainly by the minerals and rocks exhibited in this room. Unique minerals in formation and colors stand out worldwide. A spectacular aggregate of calcite crystals, weighing over 50kg, is the giant of the section. The tour ends with the Neolithic Park 3D which offers an immersive visit to the viewer.