Three climate-controlled ecosystems are brought under one roof at the Volunteer Park Conservatory. You'll travel from a garden of delicately formed, intensely colorful orchids (caged so they won't walk) to an enclosure populated with spiked cacti, and then into a room crowded with bromeliads, which seem to feed on nothing but air. Hundreds of species crowd this free observatory, each tagged with both its Latin and familiar name. Take a self-guided tour, or sign up in advance for docent-led tours that leave at 11 a.m. and 1 p.m. Tuesday–Thursday. ?Adriana Grant 1247 15th Ave. E., 322-4112, volunteerparkconservatory.org