From the Wikipedia: The Museum of the Roman Civilization (Italian "Museo della Civiltà Romana") is a museum in Rome (Esposizione Universale Roma district), devoted to the aspects of the Ancient Roman civilization.

It was designed by the architects Pietro Ascheri, D. Bernardini and Cesare Pascoletti[1] (1939-1941). Its 59 sections illustrate the history of Roman civilization, from the origins to the 4th century, with models and reproductions, as well as original material. The premises are shared with a planetarium.

At the time of my visit its main attractions were
1. a famous scale model of ancient Rome in the age of Constantine I by Italo Gismondi (Room XXXVII-XXXVIII): derived from the Forma Urbis Romae map and integrated with archeological discoveries. This model is at a 1:250 scale and is made of plaster. The model was begun in 1935 and completed in 1971. This model is today the most important reference for any serious attempt of reconstruction of the Ancient Rome
2. a complete sequence of casts of the spiral reliefs round Trajan's Column, arranged in horizontal rows at ground level to facilitate reading