Percival Lowell Milan Observatory. In 1894 Lowell chose Flagstaff, Arizona Territory, as the home of his new observatory. At an altitude of over , with few cloudy nights, and far from city lights, Flagstaff was an excellent site for astronomical observations. This marked the first time an observatory had been deliberately located in a remote, elevated place for optimal seeing. For the next fifteen years he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. Lowell published his views in three books: "Mars" (1895), "Mars and Its Canals" (1906), and "Mars As the Abode of Life"
Heidelberg-Königstuhl State Observatory Heidelberg-Königstuhl State Observatory Heidelberg-Königstuhl State Observatory () is a historic astronomical observatory located near the summit of the Königstuhl hill in the city of Heidelberg in Germany. The predecessor of the current observatory was originally opened in 1774 in the nearby city of Mannheim but degradation of observational conditions there resulted in a relocation to the Königstuhl in 1898. The observatory forms part of the Center of Astronomy of the University of Heidelberg. The Max Planck Institute for Astronomy opened on an adjacent site in 1967. Prof. Dr. Andreas Quirrenbach is the observatory's director since 2005. The instrumentation of the