Lowell Observatory is located on the outskirts of Flagstaff, Arizona, the world’s first international dark sky place. Percival Lowell is the founder of this observatory and is best known for seeing “canals” on Mars and searching for a ninth planet, which was discovered by Clyde Tombaugh at his observatory after Lowell’s passing. Lowell’s remains are on the grounds in a mausoleum. “The Home of Pluto,” as Lowell Observatory is called, is open year round, weather dependent. Visitors can make reservations to observe through the 24-inch Dyer telescope or on the Giovale Open Deck Observatory. The 24-inch Clark Refractor is also available except in winter.