High Quality Content by WIKIPEDIA articles! The Apache Point Observatory (APO) is located in the Sacramento Mountains in Sunspot, New Mexico (USA) 18 miles south of Cloudcroft. The observatory consists of the Astrophysical Research Consortium`s (ARC) 3.5-meter telescope, the Sloan Digital Sky Survey 2.5-m telescope with a 20" photometric telescope, and New Mexico State University`s 1.0-m telescope. Access to the telescopes and buildings is restricted, but the public is welcomed to stroll the grounds. The visitor`s center at Sun Spot (the National Solar Observatory) includes a model of Apache Point`s 3.5 meter telescope and actual filter plates for the Sloan telescope.