Established in 1894, Lowell Observatory is a leading astronomical and planetary science research institution, National Historical Landmark, and one of the most popular nighttime destinations in Arizona. Our astronomers and planetary scientists work to reveal our universe with advanced instruments, such as the 4.3-meter Lowell Discovery Telescope, the 5th-largest optical telescope in the continental US. State-of-the-art public telescopes provide incredible views of the cosmos, and our historical telescopes offer a look into our history of scientific progress. Admission includes constellation tours, exhibits, and access to our Giovale Open Deck Observatory. See why we are recognized as the world’s first International Dark Sky destination.