The head-clearing, heart-mending qualities of Saguaro National Park in Tucson, AZ, are obvious: the hazy Rincon Mountains, rimming 57,930 acres of sweeping desert, and not a soul around. Five trails spread across two districts range from stroll-in-the-park-with-your-grandmother easy to fiercely rigorous, with inclines rising 5,000 feet over 15 punishing miles. Saguaro is named after its most prominent plant: the majestic Saguaro cactus (a.k.a. Carnegiea Gigantea). It is huge and strange and towering, anthropomorphic in both pose and stature. These cacti can live up to 250 years and grow seven stories tall. After the sun sinks, the nocturnal programming takes over: ranger-led moonrise hikes and star-viewing parties run throughout the year (call ahead for reservations).

Whatever time of day you visit, watch where to step: We crossed paths with a rattlesnake, a fox, and several skittering tarantulas on a recent visit. Not to freak you out, but the park is also inhabited by mountain lions and Africanized honey bees, the latter of which will gladly sting you to the death if you mess with their hive. Wearing long pants and closed-toe boots are no-brainers; and packing a pair of tweezers to pluck out stray cacti spines may be your best idea ever.

3693 S. Old Spanish Rd., Tucson, AZ; 520-733-5153.