From Tucson, Hwy 86 heads west into some of the driest and emptiest parts of the Sonoran Desert. West of Sells, the Kitt Peak National Optical Observatory features the largest collection of optical telescopes in the world. Guided tours (adult/child $10/3.25; at 10am, 11:30am and 1:30pm) last about an hour.
Book two to four weeks in advance for the worthwhile nightly observing program (adult/child $49/45; no programs from mid-July to the end of August because of monsoon season) - clear, dry skies equal an awe-inspiring glimpse of the cosmos.
Dress warmly, gas up the car in Tucson (the nearest gas station is 30 miles from the observatory) and note that children under eight are not allowed, for safety reasons. The picnic area draws amateur astronomers at night.
