Kitt Peak National Observatory

High above the Sonoran desert, on the Tohono O'odham Reservation, the Kitt Peak National Observatory keeps track of the night sky with the world's largest collection of independent telescopes. Throughout the day, guides lead tours of three of the behemoths, including the world's largest solar telescope and a historic gazing dome built in 1973 to broadcast the moon explorers’ games of golf. On those chilly desert evenings, visitors can take part in the nightly observing program and view distant planets and far-off galaxies through 20- and 16-inch telescopes. Reservations are recommended; the program is quite popular and stars tend to shyly hide behind comets around large groups.