520-318-8726, recording 520-318-8200, off AZ Hwy. 86 (Ajo-Tucson Hwy.), south on State Route 386.The Visitor Center is open from 9:00 AM to 3:45 PM for daytime visitors and tours. Allow 2-3 hours. The Visitor Center is closed on Thanksgiving Day, Christmas Day, and New Years Day. Sometimes we are closed due to unforeseen circumstances beyond our control. Please check before ascending the mountain. Admission is free to the Visitor Center, but we do charge fees for daily guided tours and programs. Tour one of the world's leading observatory complexes. See the world's greatest concentration of telescopes for stellar, solar, and planetary research. Exhibits on astronomy and facility's history at visitor center with gift shop. Self-guided tour available. Variety of unique Stargazing programs and classes by reservation. No food facilities.