the centre of Rome, following the evolution of astronomical instruments, private donations, and public institutes. The Museum's collection includes, among other objects, 17th century eyepieces, 14th century telescopes, sextants for measuring the angular distance between stars, astrolabes and night dials (the oldest astrolabe dates back to the twelfth century). Moreover, there is a rich collection of armillary spheres, as well as sky and earth globes, including Mercatore's and Cassini's. The old library contains about 4000 volumes, some of which are rare and precious. For instance, there is a fourteenth century manuscript code, which collects the main astronomical works of the time, 5 incunabula, over 270 “” (16th century books) and 450 “” (17th century books). In particular, among books of ancient Astronomy, one could mention the first editions of Copernicus’ works, Ptolem's Almagestos, Sacrobosco's Sphaera, Hevel's Theatrum Cometarum, Scheiner's Rosa Ursina, and the first editions of Galilei's works. Scientific and Technological Activity OAR's scientific productivity is quite high among the 20 institutes belonging to INAF, as proved by ANVUR's National check and by Nature Index. For example, in the year between November 2016 and November 2017, OAR researchers have taken part in writing 160 articles in referees reviews, which have produced 1597 citations. From 2014 to 2017, the total number of articles is 430, with 7555 citations. The scientific activity covers all the research areas inside INAF. In the Eighties and Nineties, the scientific area which involved most researchers, and was therefore the most productive was Stellar Astrophysics, with a remarkable number of researchers who were active in the areas of Extra-galactic Astrophysics and Solar Astrophysics. Starting from the mid-Nineties, a number of researchers were recruited in the areas of Relativistic Astrophysics, and Astrophysics of the Solar System. Nowadays, the scientific areas which absorbs most young researchers are Extra-galactic Astrophysics and Cosmology. OAR researchers make use of most earth and space infrastructures, from radio to gamma rays: ALMA, NOEMA, JVLA VLT, LBT, TNG, HST Chandra, XMM, Nustar, Swift Fermi, Magic OAR Researchers are either PI or are involved in a good number of Large Programs on VLT, LBT, Chandra, and XMM. Cutting-edge research is in the following areas: Extra-galactic Astrophysics and Cosmology – Accelerated Evolution of the Universe, Dark Matter, Dark Energy The first stars, galaxies, black holes, re-ionization of the Universe Formatione and evolution of galaxies, and of their Active Galactic Nuclei (AGN) Discovery and characterization Physical processes, stellar