The Science Centre and Museum is housed in part of the monumental complex of the Rocca di Nazzano, composed of the 13th century Savelli Castle and its ancient 16th to 17th century annexes. The building, located in the public square that provides access to the fortress, contains the museum’s temporary exhibition spaces and conference rooms, the Fossil Museum and the permanent section of the River Museum. The museum is seen as a space of interest and differentiation, where the visitor can actively experience the complexity of the Tiber River ecosystem. In fact, the choice to use glass as the primary material for the project recalls the color, reflections and transparency of the water of the river to which the museum is dedicated. Our aim was to eliminate, as much as possible, the distance between the visitor and the objects on display, ensuring that the display cases become elements of great interest for the observer-visitor: the display cases are not simple ‘containers’ for objects, but real ‘environments’ that one can enter and, for example, perceive the sounds of the river environment or walk directly atop an idealized river-bed. On the first floor of the museum the display elements are composed of a continuous ‘skin’ in acid-etched glass, 2.4 meter high glass wall containing information panels, dioramas, back-lit projections and cantilevered display cases: the visitor reads the texts and observes images of the river’s ecosystem on the pages of a ‘three-dimensional’ book. On the second floor two ‘environment-display cases’ allow the visitor to enter inside and visually and acoustically experience the elements that characterize the river environment. Even the stair that connects the two levels of the museum is designed to be a part of the display system, an idealized ‘cane thicket’ of stainless steel pipes supports the stair treads, display cases and glass parapets.