The Cagliari Observatory (, or OAC) is an astronomical observatory owned and operated by Italy's Istituto Nazionale di Astrofisica (National Institute for Astrophysics, INAF). It is located 20 km away from Cagliari in Sardinia. It was founded in 1899 to study the Earth's rotation. See also List of astronomical observatories References External links Observatory home page Outreach home page Cagliari 1899 establishments in Italy